Alka-Seltzer Digest

What are the side effects you encounter while taking this medicine?
advertisement

Alka-Seltzer Digest uses

Alka-Seltzer Digest consists of Caffeine, Sodium Bicarbonate, Sodium Carbonate, Sodium Citrate, Tartaric Acid.

Caffeine:



Active ingredient (in each tablet)

Alka-Seltzer Digest (Caffeine) 200mg

Purpose

Alertness aid

Use

  • helps restore mental alertness or wakefulness when experiencing fatigue or drowsiness

Warnings

For occasional use only

Do not use

  • in children under 12 years of age
  • as a substitute for sleep

When using this product limit the use of Alka-Seltzer Digest (Caffeine) containing medications, foods, or beverages because too much Alka-Seltzer Digest (Caffeine) may cause nervousness, irritability, sleeplessness, and occasionally, rapid heartbeat. The recommended dose of this product contains about as much Alka-Seltzer Digest (Caffeine) as a cup of coffee.

Stop use and ask a doctor if fatigue or drowsiness persists or continues to recur

If pregnant or breast-feeding, ask a health professional before use.

Keep out of reach of children.

In case of overdose, get medical help or contact a Poison Control Center right away.

Directions

  • adults and children 12 years of age and over: take 1 tablet not more often than every 3 to 4 hours.

Other information

  • store at room temperature
  • avoid excessive heat (greater than 100°F) or humidity

Inactive ingredients

carnauba wax, colloidal silicon dioxide, D&C yellow #10 aluminum lake, dextrose, FD&C yellow #6 aluminum lake, hydroxypropyl methylcellulose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polysorbate 80, starch, titanium dioxide

Questions or comments?

Call toll-free 1-855-874-0970 weekdays


Display Panel Alka-Seltzer Digest (Caffeine): 16 ct. Package

Alka-Seltzer Digest (Caffeine)®

CAFFEINE ALERTNESS AID

16 TABLETS

200mg each

FUNCTIONAL Alka-Seltzer Digest (Caffeine)® for Mental Alertness

SAFE & EFFECTIVE

One tablet is equal to about a cup of coffee

Alka-Seltzer Digest (Caffeine)®

Making the Most of Every Day.®

Tamper Evident Feature: individually sealed in foil for your protection. Do not

use if foil or plastic bubble is torn or punctured.

Vivarin®, Vivarin® and design, stylization and trade dress, and FUNCTIONAL

CAFFEINE® are registered trademarks of Meda AB.

Distributed by:

Meda Consumer Healthcare Inc.

Marietta, GA 30062 ©2011 Meda AB

www.vivarin.com

16 ct. Package

Display Panel Alka-Seltzer Digest (Caffeine): 40 ct. Package

SAFE & EFFECTIVE

FUNCTIONAL Alka-Seltzer Digest (Caffeine)® for Mental Alertness

Alka-Seltzer Digest (Caffeine)®

Alka-Seltzer Digest (Caffeine) ALERTNESS AID

40 Tablets

200mg each

FUNCTIONAL Alka-Seltzer Digest (Caffeine)® for Mental Alertness

Tamper Evident Feature: Individually sealed in foil for your protection. Do not use if foil or plastic bubble is torn or punctured.

VIVARIN® helps restore mental alertness or wakefulness when experiencing fatigue or drowsiness (FDA approved uses), so you can accomplish all the things you want to do and all the things you need to do.

Vivarin®, Vivarin® and design, stylization and trade dress, and FUNCTIONAL

CAFFEINE® are registered trademarks of Meda AB.

Made in the U.S.A.

Alka-Seltzer Digest (Caffeine)®

Making the Most of Every Day.®

Distributed by:

Meda Consumer Healthcare Inc.

Marietta, GA 30062 ©2013 Meda AB

www.vivarin.com

40 ct. Package

Sodium Bicarbonate:


1 INDICATIONS AND USAGE

Alka-Seltzer Digest nitrite is indicated for sequential use with Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate for treatment of acute cyanide poisoning that is judged to be life-threatening. (1)

  • Use with caution if the diagnosis of cyanide poisoning is uncertain. (1)

1.1 Indication

Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection is indicated for sequential use with Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate for the treatment of acute cyanide poisoning that is judged to be life-threatening. When the diagnosis of cyanide poisoning is uncertain, the potentially life-threatening risks associated with Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection should be carefully weighed against the potential benefits, especially if the patient is not in extremis.

1.2 Identifying Patients with Cyanide Poisoning

Cyanide poisoning may result from inhalation, ingestion, or dermal exposure to various cyanide-containing compounds, including smoke from closed-space fires. Sources of cyanide poisoning include hydrogen cyanide and its salts, cyanogenic plants, aliphatic nitriles, and prolonged exposure to Alka-Seltzer Digest nitroprusside.

The presence and extent of cyanide poisoning are often initially unknown. There is no widely available, rapid, confirmatory cyanide blood test. Treatment decisions must be made on the basis of clinical history and signs and symptoms of cyanide intoxication. If clinical suspicion of cyanide poisoning is high, Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection and Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate Injection should be administered without delay.

Symptoms Signs
  • Headache
  • Confusion
  • Dyspnea
  • Chest Tightness
  • Nausea
  • Altered Mental Status

    (e.g., confusion, disorientation)

  • Seizures or Coma
  • Mydriasis
  • Tachypnea/Hyperpnea (early)
  • Bradypnea/Apnea (late)
  • Hypertension (early)/ Hypotension (late)
  • Cardiovascular Collapse
  • Vomiting
  • Plasma Lactate Concentration ≥ 8 mmol/L

In some settings, panic symptoms including tachypnea and vomiting may mimic early cyanide poisoning signs. The presence of altered mental status (e.g., confusion and disorientation) and/or mydriasis is suggestive of true cyanide poisoning although these signs can occur with other toxic exposures as well.

The expert advice of a regional poison control center may be obtained by calling 1-800-222-1222.

Smoke Inhalation

Not all smoke inhalation victims will have cyanide poisoning and may present with burns, trauma, and exposure to other toxic substances making a diagnosis of cyanide poisoning particularly difficult. Prior to administration of Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection, smoke-inhalation victims should be assessed for the following:

  • Exposure to fire or smoke in an enclosed area
  • Presence of soot around the mouth, nose, or oropharynx
  • Altered mental status

Although hypotension is highly suggestive of cyanide poisoning, it is only present in a small percentage of cyanide-poisoned smoke inhalation victims. Also indicative of cyanide poisoning is a plasma lactate concentration greater than or equal to 10 mmol/L (a value higher than that typically listed in the table of signs and symptoms of isolated cyanide poisoning because carbon monoxide associated with smoke inhalation also contributes to lactic acidemia). If cyanide poisoning is suspected, treatment should not be delayed to obtain a plasma lactate concentration.

1.3 Use with Other Cyanide Antidotes

Caution should be exercised when administering cyanide antidotes, other than Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate, simultaneously with Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection, as the safety of co-administration has not been established. If a decision is made to administer another cyanide antidote, other than Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate, with Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection, these drugs should not be administered concurrently in the same IV line. [see Dosage and Administration (2.2) ]

advertisement

2 DOSAGE AND ADMINISTRATION

Age Intravenous Dose of Alka-Seltzer Digest Nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate
Adults
  • Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite -10 mL of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite at the rate of 2.5 to 5 mL/minute
  • Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate - 50 mL of Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate immediately following administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite.
Children
  • Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite - 0.2 mL/kg (6 mg/kg or 6-8 mL/m2 BSA) of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite at the rate of 2.5 to 5 mL/minute not to exceed 10 mL
  • Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate - 1 mL/kg of body weight (250 mg/kg or approximately 30-40 mL/m2 of BSA) not to exceed 50 mL total dose immediately following administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite.

Redosing: If signs of cyanide poisoning reappear, repeat treatment using one-half the original dose of both Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate.

Monitoring: Blood pressure must be monitored during treatment. (2.2)

2.1 Administration Recommendation

Comprehensive treatment of acute cyanide intoxication requires support of vital functions. Administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite, followed by Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate, should be considered adjunctive to appropriate supportive therapies. Airway, ventilatory and circulatory support, and oxygen administration should not be delayed to administer Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate.

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite injection and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate injection are administered by slow intravenous injection. They should be given as early as possible after a diagnosis of acute life-threatening cyanide poisoning has been established. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should be administered first, followed immediately by Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate. Blood pressure must be monitored during infusion in both adults and children. The rate of infusion should be decreased if significant hypotension is noted.

Age Intravenous Dose of Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate
Adults
  • Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite -10 mL of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite at the rate of 2.5 to 5 mL/minute
  • Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate - 50 mL of Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate immediately following administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite.
Children
  • Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite -0.2 mL/kg (6 mg/kg or 6-8 mL/m2 BSA) of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite at the rate of 2.5 to 5 mL/minute not to exceed 10 mL
  • Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate - 1 mL/kg of body weight (250 mg/kg or approximately 30-40 mL/m2 of BSA) not to exceed 50 mL total dose immediately following administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite.

NOTE: If signs of poisoning reappear, repeat treatment using one-half the original dose of both Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate.

In adult and pediatric patients with known anemia, it is recommended that the dosage of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should be reduced proportionately to the hemoglobin concentration.

All parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

2.2 Recommended Monitoring

Patients should be monitored for at least 24-48 hours after Alka-Seltzer Digest Nitrite Injection administration for adequacy of oxygenation and perfusion and for recurrent signs and symptoms of cyanide toxicity. When possible, hemoglobin/hematocrit should be obtained when treatment is initiated. Measurements of oxygen saturation using standard pulse oximetry and calculated oxygen saturation values based on measured PO2 are unreliable in the presence of methemoglobinemia.

Methemoglobin level: Administrations of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite solely to achieve an arbitrary level of methemoglobinemia may be unnecessary and potentially hazardous. The therapeutic effects of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite do not appear to be mediated by methemoglobin formation alone and clinical responses to Alka-Seltzer Digest (Sodium Bicarbonate) nitrite administration have been reported in association with methemoglobin levels of less than 10%. Administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite beyond the initial dose should be guided primarily by clinical response to treatment (i.e., a second dose should be considered only if there is inadequate clinical response to the first dose). It is generally recommended that methemoglobin concentrations be closely monitored and kept below 30%. Serum methemoglobin levels should be monitored during treatment using co-oximetry, and administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should generally be discontinued when methemoglobin levels exceed 30%. Intravenous methylene blue and exchange transfusion have been reported in the literature as treatments for life-threatening methemoglobinemia.

2.3 Incompatibility Information

Chemical incompatibility has been reported between Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and hydroxocobalamin and these drugs should not be administered simultaneously through the same IV line. No chemical incompatibility has been reported between Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate and Alka-Seltzer Digest (Sodium Bicarbonate) nitrite, when administered sequentially through the same IV line as described in Dosage and Administration.

advertisement

3 DOSAGE FORMS AND STRENGTHS

Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection consists of:

  • One vial of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite injection, USP 300 mg/10mL (30 mg/mL)

Administration of the contents of one vial constitutes a single dose.

  • Injection, 300 mg/10 mL (30 mg/mL). (3)

4 CONTRAINDICATIONS

None

  • None. (4)

5 WARNINGS AND PRECAUTIONS

  • Methemoglobinemia: Alka-Seltzer Digest nitrite reacts with hemoglobin to form methemoglobin and should be used with caution in patients known to have anemia. Monitor oxyhemoglobin and methemoglobin levels by pulse oximetry or other measurements. Optimally, the Alka-Seltzer Digest (Sodium Bicarbonate) nitrite dose should be reduced in proportion to the oxygen carrying capacity. (5.2)
  • Smoke inhalation: Carbon monoxide contained in smoke can result in the formation of carboxyhemoglobin that can reduce the oxygen carrying capacity of the blood. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should be used with caution in patients with smoke inhalation injury because of the potential for worsening hypoxia due to methemoglobin formation. Carboxyhemoglobin and oxyhemoglobin levels should be monitored by pulse oximetry or other measurements in patients that present with evidence of smoke inhalation. Optimally, the Alka-Seltzer Digest (Sodium Bicarbonate) nitrite dose should be reduced in proportion to the oxygen carrying capacity. (5.4)

5.1 Hypotension

5.2 Methemoglobinemia

Supportive care alone may be sufficient treatment without administration of antidotes for many cases of cyanide intoxication, particularly in conscious patients without signs of severe toxicity. Patients should be closely monitored to ensure adequate perfusion and oxygenation during treatment with Alka-Seltzer Digest nitrite.

Methemoglobin levels should be monitored and oxygen administered during treatment with Alka-Seltzer Digest (Sodium Bicarbonate) nitrite whenever possible. When Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is administered to humans a wide range of methemoglobin concentrations occur. Methemoglobin concentrations as high as 58% have been reported after two 300-mg doses of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite administered to an adult. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should be used with caution in the presence of other drugs that may cause methemoglobinemia such as procaine and nitroprusside. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should be used with caution in patients who may be particularly susceptible to injury from vasodilation and its related hemodynamic sequelae. Hemodynamics should be monitored closely during and after administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite, and infusion rates should be slowed if hypotension occurs.

5.3 Anemia

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should be used with caution in patients with known anemia. Patients with anemia will form more methemoglobin (as a percentage of total hemoglobin) than persons with normal red blood cell (RBC) volumes. Optimally, these patients should receive a Alka-Seltzer Digest (Sodium Bicarbonate) nitrite dose that is reduced in proportion to their oxygen carrying capacity.

5.4 Smoke Inhalation Injury

Alka-Seltzer Digest nitrite should be used with caution in persons with smoke inhalation injury or carbon monoxide poisoning because of the potential for worsening hypoxia due to methemoglobin formation.

5.5 Neonates and Infants

Neonates and infants may be more susceptible than adults and older pediatric patients to severe methemoglobinemia when Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is administered. Reduced dosing guidelines should be followed in pediatric patients.

5.6 G6PD Deficiency

Because patients with G6PD deficiency are at increased risk of a hemolytic crisis with Alka-Seltzer Digest nitrite administration, alternative therapeutic approaches should be considered in these patients. Patients with known or suspected G6PD deficiency should be monitored for an acute drop in hematocrit. Exchange transfusion may be needed for patients with G6PD deficiency who receive Alka-Seltzer Digest (Sodium Bicarbonate) nitrite.

5.7 Use with Other Drugs

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite should be used with caution in the presence of concomitant antihypertensive medications, diuretics or volume depletion due to diuretics, or drugs known to increase vascular nitric oxide, such as PDE5 inhibitors.

advertisement

6 ADVERSE REACTIONS

There have been no controlled clinical trials conducted to systematically assess the adverse events profile of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite.

The medical literature has reported the following adverse events in association with Alka-Seltzer Digest (Sodium Bicarbonate) nitrite administration. These adverse events were not reported in the context of controlled trials or with consistent monitoring and reporting methodologies for adverse events. Therefore, frequency of occurrence of these adverse events cannot be assessed.

Cardiovascular system: syncope, hypotension, tachycardia, methemoglobinemia, palpitations, dysrhythmia

Hematological: methemoglobinemia

Central nervous system: headache, dizziness, blurred vision, seizures, confusion, coma

Gastrointestinal system: nausea, vomiting, abdominal pain

Respiratory system: tachypnea, dyspnea

Body as a Whole: anxiety, diaphoresis, lightheadedness, injection site tingling, cyanosis, acidosis, fatigue, weakness, urticaria, generalized numbness and tingling

Severe hypotension, methemoglobinemia, cardiac dysrhythmias, coma and death have been reported in patients without life-threatening cyanide poisoning but who were treated with injection of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite at doses less than twice those recommended for the treatment of cyanide poisoning.

Most common adverse reactions are:

  • Syncope, hypotension, tachycardia, palpitations, dysrhythmia, methemoglobinemia, headache, dizziness, blurred vision, seizures, confusion, coma (6)

To report SUSPECTED ADVERSE REACTIONS, contact Hope Pharmaceuticals at 1-800-755-9595 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

advertisement

7 DRUG INTERACTIONS

Formal drug interaction studies have not been conducted with Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection.

8 USE IN SPECIFIC POPULATIONS

  • Renal impairment: Alka-Seltzer Digest nitrite is substantially excreted by the kidney. The risk of toxic reactions to this drug may be greater in patients with impaired renal function. (8.6).

8.1 Pregnancy

Teratogenic Effects. Pregnancy Category C.

There are no adequate and well-controlled studies in pregnant women. Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite has caused fetal death in humans as well as animals. There are no studies in humans that have directly evaluated the potential reproductive toxicity of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite. There are two epidemiological studies conducted in Australia that report a statistically significant increase in the risk for congenital malformations, particularly in the CNS, associated with maternal consumption of water containing nitrate levels in excess of 5 ppm. Results from a case-control study in Canada suggested a trend toward an increase in the risk for CNS malformations when maternal consumption of nitrate was ≥ 26 ppm (not statistically significant).

The potential reproductive toxicity of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite exposure restricted to the prenatal period has been reported in guinea pigs, mice, and rats. There was no evidence of teratogenicity in guinea pigs, mice, or rats. However, Alka-Seltzer Digest (Sodium Bicarbonate) nitrite treatment of pregnant guinea pigs with 60 or 70 mg/kg/day resulted in abortion of the litters within 1-4 days of treatment. All animals treated subcutaneously with 70 mg/kg, Alka-Seltzer Digest (Sodium Bicarbonate) nitrite died within 60 minutes of treatment. Further studies demonstrated that a dose of 60 mg/kg resulted in measurable blood levels of methemoglobin in the dams and their fetuses for up to 6 hours post treatment. Maternal methemoglobin levels were higher than the levels in the offspring at all times measured. Based on a body surface area comparison, a 60 mg/kg dose in the guinea pig that resulted in death was only 1.7 times higher than the highest clinical dose of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite that would be used to treat cyanide poisoning (based on a body surface area comparison).

Studies testing prenatal and postnatal exposure have been reported in mice and rats. Treatment of pregnant rats via drinking water with Alka-Seltzer Digest (Sodium Bicarbonate) nitrite at concentrations of either 2000 or 3000 mg/L resulted in a dose-related increased mortality postpartum. This exposure regimen in the rat model would result in dosing of approximately 220 and 300 mg/kg/day (43 and 65 times the highest clinical dose of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite that would be used to treat cyanide poisoning, based on a body surface area comparison).

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite produces methemoglobin. Fetal hemoglobin is oxidized to methemoglobin more easily than adult hemoglobin. In addition, the fetus has lower levels of methemoglobin reductase than adults. Collectively, these data suggest that the human fetus would show greater sensitivity to methemoglobin resulting in nitrite-induced prenatal hypoxia leading to retarded development of certain neurotransmitter systems in the brain and long lasting dysfunction.

Nonteratogenic Effects: Behavioral and neurodevelopmental studies in rats suggest persistent effects of prenatal exposure to Alka-Seltzer Digest (Sodium Bicarbonate) nitrite that were detectable postnatally. Specifically, animals that were exposed prenatally to Alka-Seltzer Digest (Sodium Bicarbonate) nitrite demonstrated impaired discrimination learning behavior (both auditory and visual) and reduced long-term retention of the passive-avoidance response compared to control animals. Additional studies demonstrated a delay in the development of AchE and 5-HT positive fiber ingrowth into the hippocampal dentate gyrus and parietal neocortex during the first week of life of prenatal nitrite treated pups. These changes have been attributed to prenatal hypoxia following nitrite exposure.

8.2 Labor and Delivery

Because fetal hemoglobin is more readily oxidized to methemoglobin and lower levels of methemoglobin appear to be fatal to the fetus compared to the adult, Alka-Seltzer Digest nitrite should be used during labor and delivery only if the potential benefit justifies the potential risk to the fetus.

8.3 Nursing Mothers

It is not known whether Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is excreted in human milk. Because Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection may be administered in life-threatening situations, breast-feeding is not a contraindication to its use. Because many drugs are excreted in human milk, caution should be exercised following Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection administration to a nursing woman. There are no data to determine when breastfeeding may be safely restarted following administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite. In studies conducted with Long-Evans rats, Alka-Seltzer Digest (Sodium Bicarbonate) nitrite administered in drinking water during pregnancy and lactation resulted in severe anemia, reduced growth and increased mortality in the offspring.

8.4 Pediatric Use

There are case reports in the medical literature of Alka-Seltzer Digest nitrite in conjunction with Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate being administered to pediatric patients with cyanide poisoning; however, there have been no clinical studies to evaluate the safety or efficacy of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite in the pediatric population. As for adult patients, dosing recommendations for pediatric patients have been based on theoretical calculations of antidote detoxifying potential, extrapolation from animal experiments, and a small number of human case reports.

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite must be used with caution in patients less than 6 months of age because they may be at higher risk of developing severe methemoglobinemia compared to older children and adults. The presence of fetal hemoglobin, which is oxidized to methemoglobin more easily than adult hemoglobin, and lower methemoglobin reductase levels compared to older children and adults may contribute to risk.

Mortality attributed to Alka-Seltzer Digest (Sodium Bicarbonate) nitrite was reported following administration of an adult dose (300 mg IV followed by a second dose of 150 mg) to a 17-month old child.

8.5 Geriatric Use

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

8.6 Renal Disease

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

10 OVERDOSAGE

Large doses of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite result in severe hypotension and toxic levels of methemoglobin which may lead to cardiovascular collapse.

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite administration has been reported to cause or significantly contribute to mortality in adults at oral doses as low as 1 g and intravenous doses as low as 600 mg. A death attributed to Alka-Seltzer Digest (Sodium Bicarbonate) nitrite has been reported following administration of an adult dose (300 mg IV followed by a second dose of 150 mg) to a 17-month old child.

Cyanosis may become apparent at a methemoglobin level of 10-20%. Other clinical signs and symptoms of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite toxicity (anxiety, dyspnea, nausea, and tachycardia) can be apparent at methemoglobin levels as low as 15%. More serious signs and symptoms, including cardiac dysrhythmias, circulatory failure, and central nervous system depression are seen as methemoglobin levels increase, and levels above 70% are usually fatal.

Treatment of overdose involves supplemental oxygen and supportive measures such as exchange transfusion. Treatment of severe methemoglobinemia with intravenous methylene blue has been described in the medical literature; however, this may also cause release of cyanide bound to methemoglobin. Because hypotension appears to be mediated primarily by an increase in venous capacitance, measures to increase venous return may be most appropriate to treat hypotension.

11 DESCRIPTION

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite has the chemical name nitrous acid Alka-Seltzer Digest (Sodium Bicarbonate) salt. The chemical formula is NaNO2 and the molecular weight is 69.0. The structural formula is:

Structure of Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite

Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite Injection is a cyanide antidote which contains one 10 mL glass vial of a 3% solution of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite injection.

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite injection is a sterile aqueous solution and is intended for intravenous injection. Each vial contains 300 mg of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite in 10 mL solution (30 mg/mL). Alka-Seltzer Digest (Sodium Bicarbonate) nitrite injection is a clear solution with a pH between 7.0 and 9.0.

Chemical Structure

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Exposure to a high dose of cyanide can result in death within minutes due to the inhibition of cytochrome oxidase resulting in arrest of cellular respiration. Specifically, cyanide binds rapidly with cytochrome a3, a component of the cytochrome c oxidase complex in mitochondria. Inhibition of cytochrome a3 prevents the cell from using oxygen and forces anaerobic metabolism, resulting in lactate production, cellular hypoxia and metabolic acidosis. In massive acute cyanide poisoning, the mechanism of toxicity may involve other enzyme systems as well.

The synergy resulting from treatment of cyanide poisoning with the combination of Alka-Seltzer Digest nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate is the result of differences in their primary mechanisms of action as antidotes for cyanide poisoning.

Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is thought to exert its therapeutic effect by reacting with hemoglobin to form methemoglobin, an oxidized form of hemoglobin incapable of oxygen transport but with high affinity for cyanide. Cyanide preferentially binds to methemoglobin over cytochrome a3, forming the nontoxic cyanomethemoglobin. Methemoglobin displaces cyanide from cytochrome oxidase, allowing resumption of aerobic metabolism. The chemical reaction is as follows:

NaNO2 + Hemoglobin → Methemoglobin

HCN + Methemoglobin → Cyanomethemoglobin

Vasodilation has also been cited to account for at least part of the therapeutic effect of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite. It has been suggested that Alka-Seltzer Digest (Sodium Bicarbonate) nitrite-induced methemoglobinemia may be more efficacious against cyanide poisoning than comparable levels of methemoglobinemia induced by other oxidants. Also, Alka-Seltzer Digest (Sodium Bicarbonate) nitrite appears to retain some efficacy even when the formation of methemoglobin is inhibited by methylene blue.

Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate

The primary route of endogenous cyanide detoxification is by enzymatic transulfuration to thiocyanate (SCN-), which is relatively nontoxic and readily excreted in the urine. Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate is thought to serve as a sulfur donor in the reaction catalyzed by the enzyme rhodanese, thus enhancing the endogenous detoxification of cyanide in the following chemical reaction:

Chemical Structure

12. 2 Pharmacodynamics

Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite

When 4 mg/kg Alka-Seltzer Digest (Sodium Bicarbonate) nitrite was administered intravenously to six healthy human volunteers, the mean peak methemoglobin concentration was 7%, achieved at 30-60 minutes after injection, consistent with reports in cyanide poisoning victims. Supine systolic and diastolic blood pressures dropped approximately 20% within 10 minutes, a drop which was sustained throughout the 40 minutes of testing. This was associated with a 20 beat per minute increase in pulse rate that returned to baseline in 10 minutes. Five of these subjects were unable to withstand orthostatic testing due to fainting. One additional subject, who received a 12 mg/kg dose of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite, experienced severe cardiovascular effects and achieved a peak methemoglobin concentration of 30% at 60 minutes following injection.

Oral doses of 120 to 180 mg of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite administered to healthy volunteers caused minimal cardiovascular changes when subjects were maintained in the horizontal position. However, minutes after being placed in the upright position subjects exhibited tachycardia and hypotension with syncope.

The half life for conversion of methemoglobin to normal hemoglobin in a cyanide poisoning victim who has been administered Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is estimated to be 55 minutes.

12.3 Pharmacokinetics

Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is a strong oxidant, and reacts rapidly with hemoglobin to form methemoglobin. The pharmacokinetics of free Alka-Seltzer Digest (Sodium Bicarbonate) nitrite in humans have not been well studied. It has been reported that approximately 40% of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is excreted unchanged in the urine while the remaining 60% is metabolized to ammonia and related small molecules.

Cyanide

The apparent terminal elimination half life and volume of distribution of cyanide, in a patient treated for an acute cyanide poisoning with Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate administration, have been reported to be 19 hours and 0.41 L/kg, respectively. Additionally, an initial elimination half life of cyanide has been reported to be approximately 1-3 hours.

Thiocyanate

After detoxification, in healthy subjects, thiocyanate is excreted mainly in the urine at a rate inversely proportional to creatinine clearance. In healthy subjects, the elimination half-life and volume of distribution of thiocyanate have been reported to be 2.7 days and 0.25 L/kg, respectively. However, in subjects with renal insufficiency the reported elimination half life is approximately 9 days.

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

The potential benefit of an acute exposure to Alka-Seltzer Digest nitrite as part of a cyanide antidote outweighs concerns raised by the equivocal findings in chronic rodent studies. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite (0, 750, 1500, or 3000 ppm equivalent to average daily doses of approximately 0, 35, 70, or 130 mg/kg for males and 0, 40, 80, or 150 mg/kg for females) was orally administered to rats (Fischer 344 strain) for 2 years via drinking water. There were no significant increases in the incidence of tumor in either male or female rats. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite (0, 750, 1500, or 3000 ppm equivalent to average daily doses of approximately 0, 60, 120, or 220 mg/kg for males and 0, 45, 90, or 165 mg/kg for females) was administered to B6C3F1 mice for 2 years via the drinking water. Equivocal results were obtained in female mice. Specifically, there was a positive trend toward an increase in the incidence of squamous cell papilloma or carcinoma in the forestomach of female mice. Although the incidence of hyperplasia of the glandular stomach epithelium was significantly greater in the high-dose male mice compared to controls, there were no significant increases in tumors in the male mice. Numerous reports in the published literature indicate that Alka-Seltzer Digest (Sodium Bicarbonate) nitrite may react in vivo with secondary amines to form carcinogenic nitrosamines in the stomach. Concurrent exposure to Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and secondary amines in feed or drinking water resulted in an increase in the incidence of tumors in rodents.

Mutagenesis

Alka-Seltzer Digest (Sodium Bicarbonate) nitrite is mutagenic in S. typhimurium strains TA100, TA1530, TA1535 with and without metabolic activation; however, it was negative in strain TA98, TA102, DJ460 and E. coli strain WP2UVRA/PKM101. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite has been reported to be genotoxic to V79 hamster cells in vitro and in the mouse lymphoma assay, both assays conducted in the absence of metabolic activation. Alka-Seltzer Digest (Sodium Bicarbonate) nitrite was negative in the in vitro chromosomal aberrations assay using human peripheral blood lymphocytes. Acute administration of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite to male rats or male mice did not produce an increased incidence of micronuclei in bone marrow. Likewise, Alka-Seltzer Digest (Sodium Bicarbonate) nitrite administration to mice for 14-weeks did not result in an increase in the incidence of micronuclei in the peripheral blood.

Fertility

Clinical studies to evaluate the potential effects of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite intake on fertility of either males or females have not been reported. In contrast, multigenerational fertility and reproduction studies conducted by the National Toxicology Program did not detect any evidence of an effect of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite (0.0, 0.06, 0.12, and 0.24% weight/volume) on either fertility or any reproductive parameter in Swiss CD-1 mice. This treatment protocol resulted in approximate doses of 125, 260, and 425 mg/kg/day. The highest exposure in this mouse study is 4.6 times greater than the highest clinical dose of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite that would be used to treat cyanide poisoning (based on a body surface area comparison).

13.2 Animal Pharmacology

Due to the extreme toxicity of cyanide, experimental evaluation of treatment efficacy has predominantly been completed in animal models. The efficacy of Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate treatment alone to counteract the toxicity of cyanide was initially reported in 1895 by Lang. The efficacy of amyl nitrite treatment in cyanide poisoning of the dog model was first reported in 1888 by Pedigo. Further studies in the dog model, which demonstrated the utility of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite as a therapeutic intervention, were reported in 1929 by Mladoveanu and Gheorghiu. However, Hugs and Chen et al. independently reported upon the superior efficacy of the combination of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate in 1932-1933. Treatment consisted of intravenously administered 22.5 mg/kg (half the lethal dose) Alka-Seltzer Digest (Sodium Bicarbonate) nitrite or 1 g/kg Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate alone or in sequence immediately after subcutaneous injection of Alka-Seltzer Digest (Sodium Bicarbonate) cyanide into dogs over a range of doses. Subsequent doses of 10 mg/kg Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and/or 0.5 g/kg Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate were administered when clinical signs or symptoms of poisoning persisted or reappeared. Either therapy administered alone increased the dose of Alka-Seltzer Digest (Sodium Bicarbonate) cyanide required to cause death, and when administered together, Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate resulted in a synergistic effect in raising the lethal dose of Alka-Seltzer Digest (Sodium Bicarbonate) cyanide. The combined therapy appeared to have reduced efficacy when therapy was delayed until signs of poisoning (e.g. convulsions) appeared; however, other investigators have reported survival in dogs that were administered antidotal treatment after respiratory arrest had occurred.

Animal studies conducted in other species (e.g., rat, guinea pig, sheep, pigeon and cat) have also supported a synergistic effect of intravenous Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate in the treatment of cyanide poisoning.

While intravenous injection of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite and Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate was effective in reversing the effects of lethal doses of cyanide in dogs, intramuscular injection of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite, with or without Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate, was found not to be effective in the same setting.

14 CLINICAL STUDIES

The human data supporting the use of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite for cyanide poisoning consists primarily of published case reports. There are no randomized controlled clinical trials. Nearly all the human data describing the use of Alka-Seltzer Digest (Sodium Bicarbonate) thiosulfate report its use in conjunction with Alka-Seltzer Digest (Sodium Bicarbonate) nitrite. Dosing recommendations for humans have been based on theoretical calculations of antidote detoxifying potential, extrapolation from animal experiments, and a small number of human case reports.

There have been no human studies to prospectively and systematically evaluate the safety of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite in humans. Available human safety information is based largely on anecdotal case reports and case series of limited scope.

16 HOW SUPPLIED/STORAGE AND HANDLING

Each Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite carton (NDC 60267-311-10) consists of the following:

  • One 10 mL glass vial of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite injection 30 mg/mL (containing 300 mg of Alka-Seltzer Digest (Sodium Bicarbonate) nitrite);

Storage

Store at controlled room temperature between 20°C and 25°C (68°F to 77°F); excursions permitted from 15 to 30°C (59 to 86°F). Protect from direct light. Do not freeze.

(Note: Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate must be obtained separately.)

17 PATIENT COUNSELING INFORMATION

Alka-Seltzer Digest Nitrite Injection is indicated for acute cyanide poisoning that is judged to be life-threatening and in this setting, patients will likely be unresponsive or may have difficulty in comprehending counseling information.

17.1 Hypotension and Methemoglobin Formation

When feasible, patients should be informed of the possibility of life-threatening hypotension and methemoglobin formation.

17.2 Monitoring

Where feasible, patients should be informed of the need for close monitoring of blood pressure and oxygenation.

Manufactured by Cangene BioPharma, Inc., Baltimore, Maryland 21230 for

Hope Pharmaceuticals, Scottsdale, Arizona 85260

PRINCIPAL DISPLAY PANEL - 10 mL Vial Carton

NDC 60267-311-10

Rx Only

Alka-Seltzer Digest (Sodium Bicarbonate) Nitrite

Injection, USP

300 mg/10 mL

(30 mg/mL)

FOR INTRAVENOUS USE

SINGLE USE ONLY

Any unused portion of a vial

should be discarded.

Use with

Alka-Seltzer Digest (Sodium Bicarbonate) Thiosulfate

for Treatment of

Cyanide Poisoning

Manufactured by

CANGENE bioPharma, Inc.

Baltimore, MD for

HOPE

PHARMACEUTICALS®

Scottsdale, AZ 85260 U.S.A.

PRINCIPAL DISPLAY PANEL - 10 mL Vial Carton

Sodium Carbonate:


1 INDICATIONS AND USAGE

Alka-Seltzer Digest nitrite is indicated for sequential use with Alka-Seltzer Digest (Sodium Carbonate) thiosulfate for treatment of acute cyanide poisoning that is judged to be life-threatening. (1)

  • Use with caution if the diagnosis of cyanide poisoning is uncertain. (1)

1.1 Indication

Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection is indicated for sequential use with Alka-Seltzer Digest (Sodium Carbonate) thiosulfate for the treatment of acute cyanide poisoning that is judged to be life-threatening. When the diagnosis of cyanide poisoning is uncertain, the potentially life-threatening risks associated with Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection should be carefully weighed against the potential benefits, especially if the patient is not in extremis.

1.2 Identifying Patients with Cyanide Poisoning

Cyanide poisoning may result from inhalation, ingestion, or dermal exposure to various cyanide-containing compounds, including smoke from closed-space fires. Sources of cyanide poisoning include hydrogen cyanide and its salts, cyanogenic plants, aliphatic nitriles, and prolonged exposure to Alka-Seltzer Digest nitroprusside.

The presence and extent of cyanide poisoning are often initially unknown. There is no widely available, rapid, confirmatory cyanide blood test. Treatment decisions must be made on the basis of clinical history and signs and symptoms of cyanide intoxication. If clinical suspicion of cyanide poisoning is high, Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection and Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate Injection should be administered without delay.

Symptoms Signs
  • Headache
  • Confusion
  • Dyspnea
  • Chest Tightness
  • Nausea
  • Altered Mental Status

    (e.g., confusion, disorientation)

  • Seizures or Coma
  • Mydriasis
  • Tachypnea/Hyperpnea (early)
  • Bradypnea/Apnea (late)
  • Hypertension (early)/ Hypotension (late)
  • Cardiovascular Collapse
  • Vomiting
  • Plasma Lactate Concentration ≥ 8 mmol/L

In some settings, panic symptoms including tachypnea and vomiting may mimic early cyanide poisoning signs. The presence of altered mental status (e.g., confusion and disorientation) and/or mydriasis is suggestive of true cyanide poisoning although these signs can occur with other toxic exposures as well.

The expert advice of a regional poison control center may be obtained by calling 1-800-222-1222.

Smoke Inhalation

Not all smoke inhalation victims will have cyanide poisoning and may present with burns, trauma, and exposure to other toxic substances making a diagnosis of cyanide poisoning particularly difficult. Prior to administration of Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection, smoke-inhalation victims should be assessed for the following:

  • Exposure to fire or smoke in an enclosed area
  • Presence of soot around the mouth, nose, or oropharynx
  • Altered mental status

Although hypotension is highly suggestive of cyanide poisoning, it is only present in a small percentage of cyanide-poisoned smoke inhalation victims. Also indicative of cyanide poisoning is a plasma lactate concentration greater than or equal to 10 mmol/L (a value higher than that typically listed in the table of signs and symptoms of isolated cyanide poisoning because carbon monoxide associated with smoke inhalation also contributes to lactic acidemia). If cyanide poisoning is suspected, treatment should not be delayed to obtain a plasma lactate concentration.

1.3 Use with Other Cyanide Antidotes

Caution should be exercised when administering cyanide antidotes, other than Alka-Seltzer Digest (Sodium Carbonate) thiosulfate, simultaneously with Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection, as the safety of co-administration has not been established. If a decision is made to administer another cyanide antidote, other than Alka-Seltzer Digest (Sodium Carbonate) thiosulfate, with Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection, these drugs should not be administered concurrently in the same IV line. [see Dosage and Administration (2.2) ]

2 DOSAGE AND ADMINISTRATION

Age Intravenous Dose of Alka-Seltzer Digest Nitrite and Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate
Adults
  • Alka-Seltzer Digest (Sodium Carbonate) Nitrite -10 mL of Alka-Seltzer Digest (Sodium Carbonate) nitrite at the rate of 2.5 to 5 mL/minute
  • Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate - 50 mL of Alka-Seltzer Digest (Sodium Carbonate) thiosulfate immediately following administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite.
Children
  • Alka-Seltzer Digest (Sodium Carbonate) Nitrite - 0.2 mL/kg (6 mg/kg or 6-8 mL/m2 BSA) of Alka-Seltzer Digest (Sodium Carbonate) nitrite at the rate of 2.5 to 5 mL/minute not to exceed 10 mL
  • Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate - 1 mL/kg of body weight (250 mg/kg or approximately 30-40 mL/m2 of BSA) not to exceed 50 mL total dose immediately following administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite.

Redosing: If signs of cyanide poisoning reappear, repeat treatment using one-half the original dose of both Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate.

Monitoring: Blood pressure must be monitored during treatment. (2.2)

2.1 Administration Recommendation

Comprehensive treatment of acute cyanide intoxication requires support of vital functions. Administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite, followed by Alka-Seltzer Digest (Sodium Carbonate) thiosulfate, should be considered adjunctive to appropriate supportive therapies. Airway, ventilatory and circulatory support, and oxygen administration should not be delayed to administer Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate.

Alka-Seltzer Digest (Sodium Carbonate) nitrite injection and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate injection are administered by slow intravenous injection. They should be given as early as possible after a diagnosis of acute life-threatening cyanide poisoning has been established. Alka-Seltzer Digest (Sodium Carbonate) nitrite should be administered first, followed immediately by Alka-Seltzer Digest (Sodium Carbonate) thiosulfate. Blood pressure must be monitored during infusion in both adults and children. The rate of infusion should be decreased if significant hypotension is noted.

Age Intravenous Dose of Alka-Seltzer Digest (Sodium Carbonate) Nitrite and Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate
Adults
  • Alka-Seltzer Digest (Sodium Carbonate) Nitrite -10 mL of Alka-Seltzer Digest (Sodium Carbonate) nitrite at the rate of 2.5 to 5 mL/minute
  • Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate - 50 mL of Alka-Seltzer Digest (Sodium Carbonate) thiosulfate immediately following administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite.
Children
  • Alka-Seltzer Digest (Sodium Carbonate) Nitrite -0.2 mL/kg (6 mg/kg or 6-8 mL/m2 BSA) of Alka-Seltzer Digest (Sodium Carbonate) nitrite at the rate of 2.5 to 5 mL/minute not to exceed 10 mL
  • Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate - 1 mL/kg of body weight (250 mg/kg or approximately 30-40 mL/m2 of BSA) not to exceed 50 mL total dose immediately following administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite.

NOTE: If signs of poisoning reappear, repeat treatment using one-half the original dose of both Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate.

In adult and pediatric patients with known anemia, it is recommended that the dosage of Alka-Seltzer Digest (Sodium Carbonate) nitrite should be reduced proportionately to the hemoglobin concentration.

All parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

2.2 Recommended Monitoring

Patients should be monitored for at least 24-48 hours after Alka-Seltzer Digest Nitrite Injection administration for adequacy of oxygenation and perfusion and for recurrent signs and symptoms of cyanide toxicity. When possible, hemoglobin/hematocrit should be obtained when treatment is initiated. Measurements of oxygen saturation using standard pulse oximetry and calculated oxygen saturation values based on measured PO2 are unreliable in the presence of methemoglobinemia.

Methemoglobin level: Administrations of Alka-Seltzer Digest (Sodium Carbonate) nitrite solely to achieve an arbitrary level of methemoglobinemia may be unnecessary and potentially hazardous. The therapeutic effects of Alka-Seltzer Digest (Sodium Carbonate) nitrite do not appear to be mediated by methemoglobin formation alone and clinical responses to Alka-Seltzer Digest (Sodium Carbonate) nitrite administration have been reported in association with methemoglobin levels of less than 10%. Administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite beyond the initial dose should be guided primarily by clinical response to treatment (i.e., a second dose should be considered only if there is inadequate clinical response to the first dose). It is generally recommended that methemoglobin concentrations be closely monitored and kept below 30%. Serum methemoglobin levels should be monitored during treatment using co-oximetry, and administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite should generally be discontinued when methemoglobin levels exceed 30%. Intravenous methylene blue and exchange transfusion have been reported in the literature as treatments for life-threatening methemoglobinemia.

2.3 Incompatibility Information

Chemical incompatibility has been reported between Alka-Seltzer Digest (Sodium Carbonate) nitrite and hydroxocobalamin and these drugs should not be administered simultaneously through the same IV line. No chemical incompatibility has been reported between Alka-Seltzer Digest (Sodium Carbonate) thiosulfate and Alka-Seltzer Digest (Sodium Carbonate) nitrite, when administered sequentially through the same IV line as described in Dosage and Administration.

3 DOSAGE FORMS AND STRENGTHS

Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection consists of:

  • One vial of Alka-Seltzer Digest (Sodium Carbonate) nitrite injection, USP 300 mg/10mL (30 mg/mL)

Administration of the contents of one vial constitutes a single dose.

  • Injection, 300 mg/10 mL (30 mg/mL). (3)

4 CONTRAINDICATIONS

None

  • None. (4)

5 WARNINGS AND PRECAUTIONS

  • Methemoglobinemia: Alka-Seltzer Digest nitrite reacts with hemoglobin to form methemoglobin and should be used with caution in patients known to have anemia. Monitor oxyhemoglobin and methemoglobin levels by pulse oximetry or other measurements. Optimally, the Alka-Seltzer Digest (Sodium Carbonate) nitrite dose should be reduced in proportion to the oxygen carrying capacity. (5.2)
  • Smoke inhalation: Carbon monoxide contained in smoke can result in the formation of carboxyhemoglobin that can reduce the oxygen carrying capacity of the blood. Alka-Seltzer Digest (Sodium Carbonate) nitrite should be used with caution in patients with smoke inhalation injury because of the potential for worsening hypoxia due to methemoglobin formation. Carboxyhemoglobin and oxyhemoglobin levels should be monitored by pulse oximetry or other measurements in patients that present with evidence of smoke inhalation. Optimally, the Alka-Seltzer Digest (Sodium Carbonate) nitrite dose should be reduced in proportion to the oxygen carrying capacity. (5.4)

5.1 Hypotension

5.2 Methemoglobinemia

Supportive care alone may be sufficient treatment without administration of antidotes for many cases of cyanide intoxication, particularly in conscious patients without signs of severe toxicity. Patients should be closely monitored to ensure adequate perfusion and oxygenation during treatment with Alka-Seltzer Digest nitrite.

Methemoglobin levels should be monitored and oxygen administered during treatment with Alka-Seltzer Digest (Sodium Carbonate) nitrite whenever possible. When Alka-Seltzer Digest (Sodium Carbonate) nitrite is administered to humans a wide range of methemoglobin concentrations occur. Methemoglobin concentrations as high as 58% have been reported after two 300-mg doses of Alka-Seltzer Digest (Sodium Carbonate) nitrite administered to an adult. Alka-Seltzer Digest (Sodium Carbonate) nitrite should be used with caution in the presence of other drugs that may cause methemoglobinemia such as procaine and nitroprusside. Alka-Seltzer Digest (Sodium Carbonate) nitrite should be used with caution in patients who may be particularly susceptible to injury from vasodilation and its related hemodynamic sequelae. Hemodynamics should be monitored closely during and after administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite, and infusion rates should be slowed if hypotension occurs.

5.3 Anemia

Alka-Seltzer Digest (Sodium Carbonate) nitrite should be used with caution in patients with known anemia. Patients with anemia will form more methemoglobin (as a percentage of total hemoglobin) than persons with normal red blood cell (RBC) volumes. Optimally, these patients should receive a Alka-Seltzer Digest (Sodium Carbonate) nitrite dose that is reduced in proportion to their oxygen carrying capacity.

5.4 Smoke Inhalation Injury

Alka-Seltzer Digest nitrite should be used with caution in persons with smoke inhalation injury or carbon monoxide poisoning because of the potential for worsening hypoxia due to methemoglobin formation.

5.5 Neonates and Infants

Neonates and infants may be more susceptible than adults and older pediatric patients to severe methemoglobinemia when Alka-Seltzer Digest (Sodium Carbonate) nitrite is administered. Reduced dosing guidelines should be followed in pediatric patients.

5.6 G6PD Deficiency

Because patients with G6PD deficiency are at increased risk of a hemolytic crisis with Alka-Seltzer Digest nitrite administration, alternative therapeutic approaches should be considered in these patients. Patients with known or suspected G6PD deficiency should be monitored for an acute drop in hematocrit. Exchange transfusion may be needed for patients with G6PD deficiency who receive Alka-Seltzer Digest (Sodium Carbonate) nitrite.

5.7 Use with Other Drugs

Alka-Seltzer Digest (Sodium Carbonate) nitrite should be used with caution in the presence of concomitant antihypertensive medications, diuretics or volume depletion due to diuretics, or drugs known to increase vascular nitric oxide, such as PDE5 inhibitors.

6 ADVERSE REACTIONS

There have been no controlled clinical trials conducted to systematically assess the adverse events profile of Alka-Seltzer Digest (Sodium Carbonate) nitrite.

The medical literature has reported the following adverse events in association with Alka-Seltzer Digest (Sodium Carbonate) nitrite administration. These adverse events were not reported in the context of controlled trials or with consistent monitoring and reporting methodologies for adverse events. Therefore, frequency of occurrence of these adverse events cannot be assessed.

Cardiovascular system: syncope, hypotension, tachycardia, methemoglobinemia, palpitations, dysrhythmia

Hematological: methemoglobinemia

Central nervous system: headache, dizziness, blurred vision, seizures, confusion, coma

Gastrointestinal system: nausea, vomiting, abdominal pain

Respiratory system: tachypnea, dyspnea

Body as a Whole: anxiety, diaphoresis, lightheadedness, injection site tingling, cyanosis, acidosis, fatigue, weakness, urticaria, generalized numbness and tingling

Severe hypotension, methemoglobinemia, cardiac dysrhythmias, coma and death have been reported in patients without life-threatening cyanide poisoning but who were treated with injection of Alka-Seltzer Digest (Sodium Carbonate) nitrite at doses less than twice those recommended for the treatment of cyanide poisoning.

Most common adverse reactions are:

  • Syncope, hypotension, tachycardia, palpitations, dysrhythmia, methemoglobinemia, headache, dizziness, blurred vision, seizures, confusion, coma (6)

To report SUSPECTED ADVERSE REACTIONS, contact Hope Pharmaceuticals at 1-800-755-9595 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

7 DRUG INTERACTIONS

Formal drug interaction studies have not been conducted with Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection.

8 USE IN SPECIFIC POPULATIONS

  • Renal impairment: Alka-Seltzer Digest nitrite is substantially excreted by the kidney. The risk of toxic reactions to this drug may be greater in patients with impaired renal function. (8.6).

8.1 Pregnancy

Teratogenic Effects. Pregnancy Category C.

There are no adequate and well-controlled studies in pregnant women. Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Alka-Seltzer Digest (Sodium Carbonate) nitrite has caused fetal death in humans as well as animals. There are no studies in humans that have directly evaluated the potential reproductive toxicity of Alka-Seltzer Digest (Sodium Carbonate) nitrite. There are two epidemiological studies conducted in Australia that report a statistically significant increase in the risk for congenital malformations, particularly in the CNS, associated with maternal consumption of water containing nitrate levels in excess of 5 ppm. Results from a case-control study in Canada suggested a trend toward an increase in the risk for CNS malformations when maternal consumption of nitrate was ≥ 26 ppm (not statistically significant).

The potential reproductive toxicity of Alka-Seltzer Digest (Sodium Carbonate) nitrite exposure restricted to the prenatal period has been reported in guinea pigs, mice, and rats. There was no evidence of teratogenicity in guinea pigs, mice, or rats. However, Alka-Seltzer Digest (Sodium Carbonate) nitrite treatment of pregnant guinea pigs with 60 or 70 mg/kg/day resulted in abortion of the litters within 1-4 days of treatment. All animals treated subcutaneously with 70 mg/kg, Alka-Seltzer Digest (Sodium Carbonate) nitrite died within 60 minutes of treatment. Further studies demonstrated that a dose of 60 mg/kg resulted in measurable blood levels of methemoglobin in the dams and their fetuses for up to 6 hours post treatment. Maternal methemoglobin levels were higher than the levels in the offspring at all times measured. Based on a body surface area comparison, a 60 mg/kg dose in the guinea pig that resulted in death was only 1.7 times higher than the highest clinical dose of Alka-Seltzer Digest (Sodium Carbonate) nitrite that would be used to treat cyanide poisoning (based on a body surface area comparison).

Studies testing prenatal and postnatal exposure have been reported in mice and rats. Treatment of pregnant rats via drinking water with Alka-Seltzer Digest (Sodium Carbonate) nitrite at concentrations of either 2000 or 3000 mg/L resulted in a dose-related increased mortality postpartum. This exposure regimen in the rat model would result in dosing of approximately 220 and 300 mg/kg/day (43 and 65 times the highest clinical dose of Alka-Seltzer Digest (Sodium Carbonate) nitrite that would be used to treat cyanide poisoning, based on a body surface area comparison).

Alka-Seltzer Digest (Sodium Carbonate) nitrite produces methemoglobin. Fetal hemoglobin is oxidized to methemoglobin more easily than adult hemoglobin. In addition, the fetus has lower levels of methemoglobin reductase than adults. Collectively, these data suggest that the human fetus would show greater sensitivity to methemoglobin resulting in nitrite-induced prenatal hypoxia leading to retarded development of certain neurotransmitter systems in the brain and long lasting dysfunction.

Nonteratogenic Effects: Behavioral and neurodevelopmental studies in rats suggest persistent effects of prenatal exposure to Alka-Seltzer Digest (Sodium Carbonate) nitrite that were detectable postnatally. Specifically, animals that were exposed prenatally to Alka-Seltzer Digest (Sodium Carbonate) nitrite demonstrated impaired discrimination learning behavior (both auditory and visual) and reduced long-term retention of the passive-avoidance response compared to control animals. Additional studies demonstrated a delay in the development of AchE and 5-HT positive fiber ingrowth into the hippocampal dentate gyrus and parietal neocortex during the first week of life of prenatal nitrite treated pups. These changes have been attributed to prenatal hypoxia following nitrite exposure.

8.2 Labor and Delivery

Because fetal hemoglobin is more readily oxidized to methemoglobin and lower levels of methemoglobin appear to be fatal to the fetus compared to the adult, Alka-Seltzer Digest nitrite should be used during labor and delivery only if the potential benefit justifies the potential risk to the fetus.

8.3 Nursing Mothers

It is not known whether Alka-Seltzer Digest (Sodium Carbonate) nitrite is excreted in human milk. Because Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection may be administered in life-threatening situations, breast-feeding is not a contraindication to its use. Because many drugs are excreted in human milk, caution should be exercised following Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection administration to a nursing woman. There are no data to determine when breastfeeding may be safely restarted following administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite. In studies conducted with Long-Evans rats, Alka-Seltzer Digest (Sodium Carbonate) nitrite administered in drinking water during pregnancy and lactation resulted in severe anemia, reduced growth and increased mortality in the offspring.

8.4 Pediatric Use

There are case reports in the medical literature of Alka-Seltzer Digest nitrite in conjunction with Alka-Seltzer Digest (Sodium Carbonate) thiosulfate being administered to pediatric patients with cyanide poisoning; however, there have been no clinical studies to evaluate the safety or efficacy of Alka-Seltzer Digest (Sodium Carbonate) nitrite in the pediatric population. As for adult patients, dosing recommendations for pediatric patients have been based on theoretical calculations of antidote detoxifying potential, extrapolation from animal experiments, and a small number of human case reports.

Alka-Seltzer Digest (Sodium Carbonate) nitrite must be used with caution in patients less than 6 months of age because they may be at higher risk of developing severe methemoglobinemia compared to older children and adults. The presence of fetal hemoglobin, which is oxidized to methemoglobin more easily than adult hemoglobin, and lower methemoglobin reductase levels compared to older children and adults may contribute to risk.

Mortality attributed to Alka-Seltzer Digest (Sodium Carbonate) nitrite was reported following administration of an adult dose (300 mg IV followed by a second dose of 150 mg) to a 17-month old child.

8.5 Geriatric Use

Alka-Seltzer Digest (Sodium Carbonate) nitrite is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

8.6 Renal Disease

Alka-Seltzer Digest (Sodium Carbonate) nitrite is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

10 OVERDOSAGE

Large doses of Alka-Seltzer Digest (Sodium Carbonate) nitrite result in severe hypotension and toxic levels of methemoglobin which may lead to cardiovascular collapse.

Alka-Seltzer Digest (Sodium Carbonate) nitrite administration has been reported to cause or significantly contribute to mortality in adults at oral doses as low as 1 g and intravenous doses as low as 600 mg. A death attributed to Alka-Seltzer Digest (Sodium Carbonate) nitrite has been reported following administration of an adult dose (300 mg IV followed by a second dose of 150 mg) to a 17-month old child.

Cyanosis may become apparent at a methemoglobin level of 10-20%. Other clinical signs and symptoms of Alka-Seltzer Digest (Sodium Carbonate) nitrite toxicity (anxiety, dyspnea, nausea, and tachycardia) can be apparent at methemoglobin levels as low as 15%. More serious signs and symptoms, including cardiac dysrhythmias, circulatory failure, and central nervous system depression are seen as methemoglobin levels increase, and levels above 70% are usually fatal.

Treatment of overdose involves supplemental oxygen and supportive measures such as exchange transfusion. Treatment of severe methemoglobinemia with intravenous methylene blue has been described in the medical literature; however, this may also cause release of cyanide bound to methemoglobin. Because hypotension appears to be mediated primarily by an increase in venous capacitance, measures to increase venous return may be most appropriate to treat hypotension.

11 DESCRIPTION

Alka-Seltzer Digest (Sodium Carbonate) nitrite has the chemical name nitrous acid Alka-Seltzer Digest (Sodium Carbonate) salt. The chemical formula is NaNO2 and the molecular weight is 69.0. The structural formula is:

Structure of Alka-Seltzer Digest (Sodium Carbonate) Nitrite

Alka-Seltzer Digest (Sodium Carbonate) Nitrite Injection is a cyanide antidote which contains one 10 mL glass vial of a 3% solution of Alka-Seltzer Digest (Sodium Carbonate) nitrite injection.

Alka-Seltzer Digest (Sodium Carbonate) nitrite injection is a sterile aqueous solution and is intended for intravenous injection. Each vial contains 300 mg of Alka-Seltzer Digest (Sodium Carbonate) nitrite in 10 mL solution (30 mg/mL). Alka-Seltzer Digest (Sodium Carbonate) nitrite injection is a clear solution with a pH between 7.0 and 9.0.

Chemical Structure

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Exposure to a high dose of cyanide can result in death within minutes due to the inhibition of cytochrome oxidase resulting in arrest of cellular respiration. Specifically, cyanide binds rapidly with cytochrome a3, a component of the cytochrome c oxidase complex in mitochondria. Inhibition of cytochrome a3 prevents the cell from using oxygen and forces anaerobic metabolism, resulting in lactate production, cellular hypoxia and metabolic acidosis. In massive acute cyanide poisoning, the mechanism of toxicity may involve other enzyme systems as well.

The synergy resulting from treatment of cyanide poisoning with the combination of Alka-Seltzer Digest nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate is the result of differences in their primary mechanisms of action as antidotes for cyanide poisoning.

Alka-Seltzer Digest (Sodium Carbonate) Nitrite

Alka-Seltzer Digest (Sodium Carbonate) nitrite is thought to exert its therapeutic effect by reacting with hemoglobin to form methemoglobin, an oxidized form of hemoglobin incapable of oxygen transport but with high affinity for cyanide. Cyanide preferentially binds to methemoglobin over cytochrome a3, forming the nontoxic cyanomethemoglobin. Methemoglobin displaces cyanide from cytochrome oxidase, allowing resumption of aerobic metabolism. The chemical reaction is as follows:

NaNO2 + Hemoglobin → Methemoglobin

HCN + Methemoglobin → Cyanomethemoglobin

Vasodilation has also been cited to account for at least part of the therapeutic effect of Alka-Seltzer Digest (Sodium Carbonate) nitrite. It has been suggested that Alka-Seltzer Digest (Sodium Carbonate) nitrite-induced methemoglobinemia may be more efficacious against cyanide poisoning than comparable levels of methemoglobinemia induced by other oxidants. Also, Alka-Seltzer Digest (Sodium Carbonate) nitrite appears to retain some efficacy even when the formation of methemoglobin is inhibited by methylene blue.

Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate

The primary route of endogenous cyanide detoxification is by enzymatic transulfuration to thiocyanate (SCN-), which is relatively nontoxic and readily excreted in the urine. Alka-Seltzer Digest (Sodium Carbonate) thiosulfate is thought to serve as a sulfur donor in the reaction catalyzed by the enzyme rhodanese, thus enhancing the endogenous detoxification of cyanide in the following chemical reaction:

Chemical Structure

12. 2 Pharmacodynamics

Alka-Seltzer Digest (Sodium Carbonate) Nitrite

When 4 mg/kg Alka-Seltzer Digest (Sodium Carbonate) nitrite was administered intravenously to six healthy human volunteers, the mean peak methemoglobin concentration was 7%, achieved at 30-60 minutes after injection, consistent with reports in cyanide poisoning victims. Supine systolic and diastolic blood pressures dropped approximately 20% within 10 minutes, a drop which was sustained throughout the 40 minutes of testing. This was associated with a 20 beat per minute increase in pulse rate that returned to baseline in 10 minutes. Five of these subjects were unable to withstand orthostatic testing due to fainting. One additional subject, who received a 12 mg/kg dose of Alka-Seltzer Digest (Sodium Carbonate) nitrite, experienced severe cardiovascular effects and achieved a peak methemoglobin concentration of 30% at 60 minutes following injection.

Oral doses of 120 to 180 mg of Alka-Seltzer Digest (Sodium Carbonate) nitrite administered to healthy volunteers caused minimal cardiovascular changes when subjects were maintained in the horizontal position. However, minutes after being placed in the upright position subjects exhibited tachycardia and hypotension with syncope.

The half life for conversion of methemoglobin to normal hemoglobin in a cyanide poisoning victim who has been administered Alka-Seltzer Digest (Sodium Carbonate) nitrite is estimated to be 55 minutes.

12.3 Pharmacokinetics

Alka-Seltzer Digest (Sodium Carbonate) Nitrite

Alka-Seltzer Digest (Sodium Carbonate) nitrite is a strong oxidant, and reacts rapidly with hemoglobin to form methemoglobin. The pharmacokinetics of free Alka-Seltzer Digest (Sodium Carbonate) nitrite in humans have not been well studied. It has been reported that approximately 40% of Alka-Seltzer Digest (Sodium Carbonate) nitrite is excreted unchanged in the urine while the remaining 60% is metabolized to ammonia and related small molecules.

Cyanide

The apparent terminal elimination half life and volume of distribution of cyanide, in a patient treated for an acute cyanide poisoning with Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate administration, have been reported to be 19 hours and 0.41 L/kg, respectively. Additionally, an initial elimination half life of cyanide has been reported to be approximately 1-3 hours.

Thiocyanate

After detoxification, in healthy subjects, thiocyanate is excreted mainly in the urine at a rate inversely proportional to creatinine clearance. In healthy subjects, the elimination half-life and volume of distribution of thiocyanate have been reported to be 2.7 days and 0.25 L/kg, respectively. However, in subjects with renal insufficiency the reported elimination half life is approximately 9 days.

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

The potential benefit of an acute exposure to Alka-Seltzer Digest nitrite as part of a cyanide antidote outweighs concerns raised by the equivocal findings in chronic rodent studies. Alka-Seltzer Digest (Sodium Carbonate) nitrite (0, 750, 1500, or 3000 ppm equivalent to average daily doses of approximately 0, 35, 70, or 130 mg/kg for males and 0, 40, 80, or 150 mg/kg for females) was orally administered to rats (Fischer 344 strain) for 2 years via drinking water. There were no significant increases in the incidence of tumor in either male or female rats. Alka-Seltzer Digest (Sodium Carbonate) nitrite (0, 750, 1500, or 3000 ppm equivalent to average daily doses of approximately 0, 60, 120, or 220 mg/kg for males and 0, 45, 90, or 165 mg/kg for females) was administered to B6C3F1 mice for 2 years via the drinking water. Equivocal results were obtained in female mice. Specifically, there was a positive trend toward an increase in the incidence of squamous cell papilloma or carcinoma in the forestomach of female mice. Although the incidence of hyperplasia of the glandular stomach epithelium was significantly greater in the high-dose male mice compared to controls, there were no significant increases in tumors in the male mice. Numerous reports in the published literature indicate that Alka-Seltzer Digest (Sodium Carbonate) nitrite may react in vivo with secondary amines to form carcinogenic nitrosamines in the stomach. Concurrent exposure to Alka-Seltzer Digest (Sodium Carbonate) nitrite and secondary amines in feed or drinking water resulted in an increase in the incidence of tumors in rodents.

Mutagenesis

Alka-Seltzer Digest (Sodium Carbonate) nitrite is mutagenic in S. typhimurium strains TA100, TA1530, TA1535 with and without metabolic activation; however, it was negative in strain TA98, TA102, DJ460 and E. coli strain WP2UVRA/PKM101. Alka-Seltzer Digest (Sodium Carbonate) nitrite has been reported to be genotoxic to V79 hamster cells in vitro and in the mouse lymphoma assay, both assays conducted in the absence of metabolic activation. Alka-Seltzer Digest (Sodium Carbonate) nitrite was negative in the in vitro chromosomal aberrations assay using human peripheral blood lymphocytes. Acute administration of Alka-Seltzer Digest (Sodium Carbonate) nitrite to male rats or male mice did not produce an increased incidence of micronuclei in bone marrow. Likewise, Alka-Seltzer Digest (Sodium Carbonate) nitrite administration to mice for 14-weeks did not result in an increase in the incidence of micronuclei in the peripheral blood.

Fertility

Clinical studies to evaluate the potential effects of Alka-Seltzer Digest (Sodium Carbonate) nitrite intake on fertility of either males or females have not been reported. In contrast, multigenerational fertility and reproduction studies conducted by the National Toxicology Program did not detect any evidence of an effect of Alka-Seltzer Digest (Sodium Carbonate) nitrite (0.0, 0.06, 0.12, and 0.24% weight/volume) on either fertility or any reproductive parameter in Swiss CD-1 mice. This treatment protocol resulted in approximate doses of 125, 260, and 425 mg/kg/day. The highest exposure in this mouse study is 4.6 times greater than the highest clinical dose of Alka-Seltzer Digest (Sodium Carbonate) nitrite that would be used to treat cyanide poisoning (based on a body surface area comparison).

13.2 Animal Pharmacology

Due to the extreme toxicity of cyanide, experimental evaluation of treatment efficacy has predominantly been completed in animal models. The efficacy of Alka-Seltzer Digest (Sodium Carbonate) thiosulfate treatment alone to counteract the toxicity of cyanide was initially reported in 1895 by Lang. The efficacy of amyl nitrite treatment in cyanide poisoning of the dog model was first reported in 1888 by Pedigo. Further studies in the dog model, which demonstrated the utility of Alka-Seltzer Digest (Sodium Carbonate) nitrite as a therapeutic intervention, were reported in 1929 by Mladoveanu and Gheorghiu. However, Hugs and Chen et al. independently reported upon the superior efficacy of the combination of Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate in 1932-1933. Treatment consisted of intravenously administered 22.5 mg/kg (half the lethal dose) Alka-Seltzer Digest (Sodium Carbonate) nitrite or 1 g/kg Alka-Seltzer Digest (Sodium Carbonate) thiosulfate alone or in sequence immediately after subcutaneous injection of Alka-Seltzer Digest (Sodium Carbonate) cyanide into dogs over a range of doses. Subsequent doses of 10 mg/kg Alka-Seltzer Digest (Sodium Carbonate) nitrite and/or 0.5 g/kg Alka-Seltzer Digest (Sodium Carbonate) thiosulfate were administered when clinical signs or symptoms of poisoning persisted or reappeared. Either therapy administered alone increased the dose of Alka-Seltzer Digest (Sodium Carbonate) cyanide required to cause death, and when administered together, Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate resulted in a synergistic effect in raising the lethal dose of Alka-Seltzer Digest (Sodium Carbonate) cyanide. The combined therapy appeared to have reduced efficacy when therapy was delayed until signs of poisoning (e.g. convulsions) appeared; however, other investigators have reported survival in dogs that were administered antidotal treatment after respiratory arrest had occurred.

Animal studies conducted in other species (e.g., rat, guinea pig, sheep, pigeon and cat) have also supported a synergistic effect of intravenous Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate in the treatment of cyanide poisoning.

While intravenous injection of Alka-Seltzer Digest (Sodium Carbonate) nitrite and Alka-Seltzer Digest (Sodium Carbonate) thiosulfate was effective in reversing the effects of lethal doses of cyanide in dogs, intramuscular injection of Alka-Seltzer Digest (Sodium Carbonate) nitrite, with or without Alka-Seltzer Digest (Sodium Carbonate) thiosulfate, was found not to be effective in the same setting.

14 CLINICAL STUDIES

The human data supporting the use of Alka-Seltzer Digest (Sodium Carbonate) nitrite for cyanide poisoning consists primarily of published case reports. There are no randomized controlled clinical trials. Nearly all the human data describing the use of Alka-Seltzer Digest (Sodium Carbonate) thiosulfate report its use in conjunction with Alka-Seltzer Digest (Sodium Carbonate) nitrite. Dosing recommendations for humans have been based on theoretical calculations of antidote detoxifying potential, extrapolation from animal experiments, and a small number of human case reports.

There have been no human studies to prospectively and systematically evaluate the safety of Alka-Seltzer Digest (Sodium Carbonate) nitrite in humans. Available human safety information is based largely on anecdotal case reports and case series of limited scope.

16 HOW SUPPLIED/STORAGE AND HANDLING

Each Alka-Seltzer Digest (Sodium Carbonate) Nitrite carton (NDC 60267-311-10) consists of the following:

  • One 10 mL glass vial of Alka-Seltzer Digest (Sodium Carbonate) nitrite injection 30 mg/mL (containing 300 mg of Alka-Seltzer Digest (Sodium Carbonate) nitrite);

Storage

Store at controlled room temperature between 20°C and 25°C (68°F to 77°F); excursions permitted from 15 to 30°C (59 to 86°F). Protect from direct light. Do not freeze.

(Note: Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate must be obtained separately.)

17 PATIENT COUNSELING INFORMATION

Alka-Seltzer Digest Nitrite Injection is indicated for acute cyanide poisoning that is judged to be life-threatening and in this setting, patients will likely be unresponsive or may have difficulty in comprehending counseling information.

17.1 Hypotension and Methemoglobin Formation

When feasible, patients should be informed of the possibility of life-threatening hypotension and methemoglobin formation.

17.2 Monitoring

Where feasible, patients should be informed of the need for close monitoring of blood pressure and oxygenation.

Manufactured by Cangene BioPharma, Inc., Baltimore, Maryland 21230 for

Hope Pharmaceuticals, Scottsdale, Arizona 85260

PRINCIPAL DISPLAY PANEL - 10 mL Vial Carton

NDC 60267-311-10

Rx Only

Alka-Seltzer Digest (Sodium Carbonate) Nitrite

Injection, USP

300 mg/10 mL

(30 mg/mL)

FOR INTRAVENOUS USE

SINGLE USE ONLY

Any unused portion of a vial

should be discarded.

Use with

Alka-Seltzer Digest (Sodium Carbonate) Thiosulfate

for Treatment of

Cyanide Poisoning

Manufactured by

CANGENE bioPharma, Inc.

Baltimore, MD for

HOPE

PHARMACEUTICALS®

Scottsdale, AZ 85260 U.S.A.

PRINCIPAL DISPLAY PANEL - 10 mL Vial Carton

Sodium Citrate:


1 INDICATIONS AND USAGE

Alka-Seltzer Digest nitrite is indicated for sequential use with Alka-Seltzer Digest (Sodium Citrate) thiosulfate for treatment of acute cyanide poisoning that is judged to be life-threatening. (1)

  • Use with caution if the diagnosis of cyanide poisoning is uncertain. (1)

1.1 Indication

Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection is indicated for sequential use with Alka-Seltzer Digest (Sodium Citrate) thiosulfate for the treatment of acute cyanide poisoning that is judged to be life-threatening. When the diagnosis of cyanide poisoning is uncertain, the potentially life-threatening risks associated with Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection should be carefully weighed against the potential benefits, especially if the patient is not in extremis.

1.2 Identifying Patients with Cyanide Poisoning

Cyanide poisoning may result from inhalation, ingestion, or dermal exposure to various cyanide-containing compounds, including smoke from closed-space fires. Sources of cyanide poisoning include hydrogen cyanide and its salts, cyanogenic plants, aliphatic nitriles, and prolonged exposure to Alka-Seltzer Digest nitroprusside.

The presence and extent of cyanide poisoning are often initially unknown. There is no widely available, rapid, confirmatory cyanide blood test. Treatment decisions must be made on the basis of clinical history and signs and symptoms of cyanide intoxication. If clinical suspicion of cyanide poisoning is high, Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection and Alka-Seltzer Digest (Sodium Citrate) Thiosulfate Injection should be administered without delay.

Symptoms Signs
  • Headache
  • Confusion
  • Dyspnea
  • Chest Tightness
  • Nausea
  • Altered Mental Status

    (e.g., confusion, disorientation)

  • Seizures or Coma
  • Mydriasis
  • Tachypnea/Hyperpnea (early)
  • Bradypnea/Apnea (late)
  • Hypertension (early)/ Hypotension (late)
  • Cardiovascular Collapse
  • Vomiting
  • Plasma Lactate Concentration ≥ 8 mmol/L

In some settings, panic symptoms including tachypnea and vomiting may mimic early cyanide poisoning signs. The presence of altered mental status (e.g., confusion and disorientation) and/or mydriasis is suggestive of true cyanide poisoning although these signs can occur with other toxic exposures as well.

The expert advice of a regional poison control center may be obtained by calling 1-800-222-1222.

Smoke Inhalation

Not all smoke inhalation victims will have cyanide poisoning and may present with burns, trauma, and exposure to other toxic substances making a diagnosis of cyanide poisoning particularly difficult. Prior to administration of Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection, smoke-inhalation victims should be assessed for the following:

  • Exposure to fire or smoke in an enclosed area
  • Presence of soot around the mouth, nose, or oropharynx
  • Altered mental status

Although hypotension is highly suggestive of cyanide poisoning, it is only present in a small percentage of cyanide-poisoned smoke inhalation victims. Also indicative of cyanide poisoning is a plasma lactate concentration greater than or equal to 10 mmol/L (a value higher than that typically listed in the table of signs and symptoms of isolated cyanide poisoning because carbon monoxide associated with smoke inhalation also contributes to lactic acidemia). If cyanide poisoning is suspected, treatment should not be delayed to obtain a plasma lactate concentration.

1.3 Use with Other Cyanide Antidotes

Caution should be exercised when administering cyanide antidotes, other than Alka-Seltzer Digest (Sodium Citrate) thiosulfate, simultaneously with Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection, as the safety of co-administration has not been established. If a decision is made to administer another cyanide antidote, other than Alka-Seltzer Digest (Sodium Citrate) thiosulfate, with Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection, these drugs should not be administered concurrently in the same IV line. [see Dosage and Administration (2.2) ]

2 DOSAGE AND ADMINISTRATION

Age Intravenous Dose of Alka-Seltzer Digest Nitrite and Alka-Seltzer Digest (Sodium Citrate) Thiosulfate
Adults
  • Alka-Seltzer Digest (Sodium Citrate) Nitrite -10 mL of Alka-Seltzer Digest (Sodium Citrate) nitrite at the rate of 2.5 to 5 mL/minute
  • Alka-Seltzer Digest (Sodium Citrate) Thiosulfate - 50 mL of Alka-Seltzer Digest (Sodium Citrate) thiosulfate immediately following administration of Alka-Seltzer Digest (Sodium Citrate) nitrite.
Children
  • Alka-Seltzer Digest (Sodium Citrate) Nitrite - 0.2 mL/kg (6 mg/kg or 6-8 mL/m2 BSA) of Alka-Seltzer Digest (Sodium Citrate) nitrite at the rate of 2.5 to 5 mL/minute not to exceed 10 mL
  • Alka-Seltzer Digest (Sodium Citrate) Thiosulfate - 1 mL/kg of body weight (250 mg/kg or approximately 30-40 mL/m2 of BSA) not to exceed 50 mL total dose immediately following administration of Alka-Seltzer Digest (Sodium Citrate) nitrite.

Redosing: If signs of cyanide poisoning reappear, repeat treatment using one-half the original dose of both Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate.

Monitoring: Blood pressure must be monitored during treatment. (2.2)

2.1 Administration Recommendation

Comprehensive treatment of acute cyanide intoxication requires support of vital functions. Administration of Alka-Seltzer Digest (Sodium Citrate) nitrite, followed by Alka-Seltzer Digest (Sodium Citrate) thiosulfate, should be considered adjunctive to appropriate supportive therapies. Airway, ventilatory and circulatory support, and oxygen administration should not be delayed to administer Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate.

Alka-Seltzer Digest (Sodium Citrate) nitrite injection and Alka-Seltzer Digest (Sodium Citrate) thiosulfate injection are administered by slow intravenous injection. They should be given as early as possible after a diagnosis of acute life-threatening cyanide poisoning has been established. Alka-Seltzer Digest (Sodium Citrate) nitrite should be administered first, followed immediately by Alka-Seltzer Digest (Sodium Citrate) thiosulfate. Blood pressure must be monitored during infusion in both adults and children. The rate of infusion should be decreased if significant hypotension is noted.

Age Intravenous Dose of Alka-Seltzer Digest (Sodium Citrate) Nitrite and Alka-Seltzer Digest (Sodium Citrate) Thiosulfate
Adults
  • Alka-Seltzer Digest (Sodium Citrate) Nitrite -10 mL of Alka-Seltzer Digest (Sodium Citrate) nitrite at the rate of 2.5 to 5 mL/minute
  • Alka-Seltzer Digest (Sodium Citrate) Thiosulfate - 50 mL of Alka-Seltzer Digest (Sodium Citrate) thiosulfate immediately following administration of Alka-Seltzer Digest (Sodium Citrate) nitrite.
Children
  • Alka-Seltzer Digest (Sodium Citrate) Nitrite -0.2 mL/kg (6 mg/kg or 6-8 mL/m2 BSA) of Alka-Seltzer Digest (Sodium Citrate) nitrite at the rate of 2.5 to 5 mL/minute not to exceed 10 mL
  • Alka-Seltzer Digest (Sodium Citrate) Thiosulfate - 1 mL/kg of body weight (250 mg/kg or approximately 30-40 mL/m2 of BSA) not to exceed 50 mL total dose immediately following administration of Alka-Seltzer Digest (Sodium Citrate) nitrite.

NOTE: If signs of poisoning reappear, repeat treatment using one-half the original dose of both Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate.

In adult and pediatric patients with known anemia, it is recommended that the dosage of Alka-Seltzer Digest (Sodium Citrate) nitrite should be reduced proportionately to the hemoglobin concentration.

All parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

2.2 Recommended Monitoring

Patients should be monitored for at least 24-48 hours after Alka-Seltzer Digest Nitrite Injection administration for adequacy of oxygenation and perfusion and for recurrent signs and symptoms of cyanide toxicity. When possible, hemoglobin/hematocrit should be obtained when treatment is initiated. Measurements of oxygen saturation using standard pulse oximetry and calculated oxygen saturation values based on measured PO2 are unreliable in the presence of methemoglobinemia.

Methemoglobin level: Administrations of Alka-Seltzer Digest (Sodium Citrate) nitrite solely to achieve an arbitrary level of methemoglobinemia may be unnecessary and potentially hazardous. The therapeutic effects of Alka-Seltzer Digest (Sodium Citrate) nitrite do not appear to be mediated by methemoglobin formation alone and clinical responses to Alka-Seltzer Digest (Sodium Citrate) nitrite administration have been reported in association with methemoglobin levels of less than 10%. Administration of Alka-Seltzer Digest (Sodium Citrate) nitrite beyond the initial dose should be guided primarily by clinical response to treatment (i.e., a second dose should be considered only if there is inadequate clinical response to the first dose). It is generally recommended that methemoglobin concentrations be closely monitored and kept below 30%. Serum methemoglobin levels should be monitored during treatment using co-oximetry, and administration of Alka-Seltzer Digest (Sodium Citrate) nitrite should generally be discontinued when methemoglobin levels exceed 30%. Intravenous methylene blue and exchange transfusion have been reported in the literature as treatments for life-threatening methemoglobinemia.

2.3 Incompatibility Information

Chemical incompatibility has been reported between Alka-Seltzer Digest (Sodium Citrate) nitrite and hydroxocobalamin and these drugs should not be administered simultaneously through the same IV line. No chemical incompatibility has been reported between Alka-Seltzer Digest (Sodium Citrate) thiosulfate and Alka-Seltzer Digest (Sodium Citrate) nitrite, when administered sequentially through the same IV line as described in Dosage and Administration.

3 DOSAGE FORMS AND STRENGTHS

Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection consists of:

  • One vial of Alka-Seltzer Digest (Sodium Citrate) nitrite injection, USP 300 mg/10mL (30 mg/mL)

Administration of the contents of one vial constitutes a single dose.

  • Injection, 300 mg/10 mL (30 mg/mL). (3)

4 CONTRAINDICATIONS

None

  • None. (4)

5 WARNINGS AND PRECAUTIONS

  • Methemoglobinemia: Alka-Seltzer Digest nitrite reacts with hemoglobin to form methemoglobin and should be used with caution in patients known to have anemia. Monitor oxyhemoglobin and methemoglobin levels by pulse oximetry or other measurements. Optimally, the Alka-Seltzer Digest (Sodium Citrate) nitrite dose should be reduced in proportion to the oxygen carrying capacity. (5.2)
  • Smoke inhalation: Carbon monoxide contained in smoke can result in the formation of carboxyhemoglobin that can reduce the oxygen carrying capacity of the blood. Alka-Seltzer Digest (Sodium Citrate) nitrite should be used with caution in patients with smoke inhalation injury because of the potential for worsening hypoxia due to methemoglobin formation. Carboxyhemoglobin and oxyhemoglobin levels should be monitored by pulse oximetry or other measurements in patients that present with evidence of smoke inhalation. Optimally, the Alka-Seltzer Digest (Sodium Citrate) nitrite dose should be reduced in proportion to the oxygen carrying capacity. (5.4)

5.1 Hypotension

5.2 Methemoglobinemia

Supportive care alone may be sufficient treatment without administration of antidotes for many cases of cyanide intoxication, particularly in conscious patients without signs of severe toxicity. Patients should be closely monitored to ensure adequate perfusion and oxygenation during treatment with Alka-Seltzer Digest nitrite.

Methemoglobin levels should be monitored and oxygen administered during treatment with Alka-Seltzer Digest (Sodium Citrate) nitrite whenever possible. When Alka-Seltzer Digest (Sodium Citrate) nitrite is administered to humans a wide range of methemoglobin concentrations occur. Methemoglobin concentrations as high as 58% have been reported after two 300-mg doses of Alka-Seltzer Digest (Sodium Citrate) nitrite administered to an adult. Alka-Seltzer Digest (Sodium Citrate) nitrite should be used with caution in the presence of other drugs that may cause methemoglobinemia such as procaine and nitroprusside. Alka-Seltzer Digest (Sodium Citrate) nitrite should be used with caution in patients who may be particularly susceptible to injury from vasodilation and its related hemodynamic sequelae. Hemodynamics should be monitored closely during and after administration of Alka-Seltzer Digest (Sodium Citrate) nitrite, and infusion rates should be slowed if hypotension occurs.

5.3 Anemia

Alka-Seltzer Digest (Sodium Citrate) nitrite should be used with caution in patients with known anemia. Patients with anemia will form more methemoglobin (as a percentage of total hemoglobin) than persons with normal red blood cell (RBC) volumes. Optimally, these patients should receive a Alka-Seltzer Digest (Sodium Citrate) nitrite dose that is reduced in proportion to their oxygen carrying capacity.

5.4 Smoke Inhalation Injury

Alka-Seltzer Digest nitrite should be used with caution in persons with smoke inhalation injury or carbon monoxide poisoning because of the potential for worsening hypoxia due to methemoglobin formation.

5.5 Neonates and Infants

Neonates and infants may be more susceptible than adults and older pediatric patients to severe methemoglobinemia when Alka-Seltzer Digest (Sodium Citrate) nitrite is administered. Reduced dosing guidelines should be followed in pediatric patients.

5.6 G6PD Deficiency

Because patients with G6PD deficiency are at increased risk of a hemolytic crisis with Alka-Seltzer Digest nitrite administration, alternative therapeutic approaches should be considered in these patients. Patients with known or suspected G6PD deficiency should be monitored for an acute drop in hematocrit. Exchange transfusion may be needed for patients with G6PD deficiency who receive Alka-Seltzer Digest (Sodium Citrate) nitrite.

5.7 Use with Other Drugs

Alka-Seltzer Digest (Sodium Citrate) nitrite should be used with caution in the presence of concomitant antihypertensive medications, diuretics or volume depletion due to diuretics, or drugs known to increase vascular nitric oxide, such as PDE5 inhibitors.

6 ADVERSE REACTIONS

There have been no controlled clinical trials conducted to systematically assess the adverse events profile of Alka-Seltzer Digest (Sodium Citrate) nitrite.

The medical literature has reported the following adverse events in association with Alka-Seltzer Digest (Sodium Citrate) nitrite administration. These adverse events were not reported in the context of controlled trials or with consistent monitoring and reporting methodologies for adverse events. Therefore, frequency of occurrence of these adverse events cannot be assessed.

Cardiovascular system: syncope, hypotension, tachycardia, methemoglobinemia, palpitations, dysrhythmia

Hematological: methemoglobinemia

Central nervous system: headache, dizziness, blurred vision, seizures, confusion, coma

Gastrointestinal system: nausea, vomiting, abdominal pain

Respiratory system: tachypnea, dyspnea

Body as a Whole: anxiety, diaphoresis, lightheadedness, injection site tingling, cyanosis, acidosis, fatigue, weakness, urticaria, generalized numbness and tingling

Severe hypotension, methemoglobinemia, cardiac dysrhythmias, coma and death have been reported in patients without life-threatening cyanide poisoning but who were treated with injection of Alka-Seltzer Digest (Sodium Citrate) nitrite at doses less than twice those recommended for the treatment of cyanide poisoning.

Most common adverse reactions are:

  • Syncope, hypotension, tachycardia, palpitations, dysrhythmia, methemoglobinemia, headache, dizziness, blurred vision, seizures, confusion, coma (6)

To report SUSPECTED ADVERSE REACTIONS, contact Hope Pharmaceuticals at 1-800-755-9595 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

7 DRUG INTERACTIONS

Formal drug interaction studies have not been conducted with Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection.

8 USE IN SPECIFIC POPULATIONS

  • Renal impairment: Alka-Seltzer Digest nitrite is substantially excreted by the kidney. The risk of toxic reactions to this drug may be greater in patients with impaired renal function. (8.6).

8.1 Pregnancy

Teratogenic Effects. Pregnancy Category C.

There are no adequate and well-controlled studies in pregnant women. Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Alka-Seltzer Digest (Sodium Citrate) nitrite has caused fetal death in humans as well as animals. There are no studies in humans that have directly evaluated the potential reproductive toxicity of Alka-Seltzer Digest (Sodium Citrate) nitrite. There are two epidemiological studies conducted in Australia that report a statistically significant increase in the risk for congenital malformations, particularly in the CNS, associated with maternal consumption of water containing nitrate levels in excess of 5 ppm. Results from a case-control study in Canada suggested a trend toward an increase in the risk for CNS malformations when maternal consumption of nitrate was ≥ 26 ppm (not statistically significant).

The potential reproductive toxicity of Alka-Seltzer Digest (Sodium Citrate) nitrite exposure restricted to the prenatal period has been reported in guinea pigs, mice, and rats. There was no evidence of teratogenicity in guinea pigs, mice, or rats. However, Alka-Seltzer Digest (Sodium Citrate) nitrite treatment of pregnant guinea pigs with 60 or 70 mg/kg/day resulted in abortion of the litters within 1-4 days of treatment. All animals treated subcutaneously with 70 mg/kg, Alka-Seltzer Digest (Sodium Citrate) nitrite died within 60 minutes of treatment. Further studies demonstrated that a dose of 60 mg/kg resulted in measurable blood levels of methemoglobin in the dams and their fetuses for up to 6 hours post treatment. Maternal methemoglobin levels were higher than the levels in the offspring at all times measured. Based on a body surface area comparison, a 60 mg/kg dose in the guinea pig that resulted in death was only 1.7 times higher than the highest clinical dose of Alka-Seltzer Digest (Sodium Citrate) nitrite that would be used to treat cyanide poisoning (based on a body surface area comparison).

Studies testing prenatal and postnatal exposure have been reported in mice and rats. Treatment of pregnant rats via drinking water with Alka-Seltzer Digest (Sodium Citrate) nitrite at concentrations of either 2000 or 3000 mg/L resulted in a dose-related increased mortality postpartum. This exposure regimen in the rat model would result in dosing of approximately 220 and 300 mg/kg/day (43 and 65 times the highest clinical dose of Alka-Seltzer Digest (Sodium Citrate) nitrite that would be used to treat cyanide poisoning, based on a body surface area comparison).

Alka-Seltzer Digest (Sodium Citrate) nitrite produces methemoglobin. Fetal hemoglobin is oxidized to methemoglobin more easily than adult hemoglobin. In addition, the fetus has lower levels of methemoglobin reductase than adults. Collectively, these data suggest that the human fetus would show greater sensitivity to methemoglobin resulting in nitrite-induced prenatal hypoxia leading to retarded development of certain neurotransmitter systems in the brain and long lasting dysfunction.

Nonteratogenic Effects: Behavioral and neurodevelopmental studies in rats suggest persistent effects of prenatal exposure to Alka-Seltzer Digest (Sodium Citrate) nitrite that were detectable postnatally. Specifically, animals that were exposed prenatally to Alka-Seltzer Digest (Sodium Citrate) nitrite demonstrated impaired discrimination learning behavior (both auditory and visual) and reduced long-term retention of the passive-avoidance response compared to control animals. Additional studies demonstrated a delay in the development of AchE and 5-HT positive fiber ingrowth into the hippocampal dentate gyrus and parietal neocortex during the first week of life of prenatal nitrite treated pups. These changes have been attributed to prenatal hypoxia following nitrite exposure.

8.2 Labor and Delivery

Because fetal hemoglobin is more readily oxidized to methemoglobin and lower levels of methemoglobin appear to be fatal to the fetus compared to the adult, Alka-Seltzer Digest nitrite should be used during labor and delivery only if the potential benefit justifies the potential risk to the fetus.

8.3 Nursing Mothers

It is not known whether Alka-Seltzer Digest (Sodium Citrate) nitrite is excreted in human milk. Because Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection may be administered in life-threatening situations, breast-feeding is not a contraindication to its use. Because many drugs are excreted in human milk, caution should be exercised following Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection administration to a nursing woman. There are no data to determine when breastfeeding may be safely restarted following administration of Alka-Seltzer Digest (Sodium Citrate) nitrite. In studies conducted with Long-Evans rats, Alka-Seltzer Digest (Sodium Citrate) nitrite administered in drinking water during pregnancy and lactation resulted in severe anemia, reduced growth and increased mortality in the offspring.

8.4 Pediatric Use

There are case reports in the medical literature of Alka-Seltzer Digest nitrite in conjunction with Alka-Seltzer Digest (Sodium Citrate) thiosulfate being administered to pediatric patients with cyanide poisoning; however, there have been no clinical studies to evaluate the safety or efficacy of Alka-Seltzer Digest (Sodium Citrate) nitrite in the pediatric population. As for adult patients, dosing recommendations for pediatric patients have been based on theoretical calculations of antidote detoxifying potential, extrapolation from animal experiments, and a small number of human case reports.

Alka-Seltzer Digest (Sodium Citrate) nitrite must be used with caution in patients less than 6 months of age because they may be at higher risk of developing severe methemoglobinemia compared to older children and adults. The presence of fetal hemoglobin, which is oxidized to methemoglobin more easily than adult hemoglobin, and lower methemoglobin reductase levels compared to older children and adults may contribute to risk.

Mortality attributed to Alka-Seltzer Digest (Sodium Citrate) nitrite was reported following administration of an adult dose (300 mg IV followed by a second dose of 150 mg) to a 17-month old child.

8.5 Geriatric Use

Alka-Seltzer Digest (Sodium Citrate) nitrite is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

8.6 Renal Disease

Alka-Seltzer Digest (Sodium Citrate) nitrite is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

10 OVERDOSAGE

Large doses of Alka-Seltzer Digest (Sodium Citrate) nitrite result in severe hypotension and toxic levels of methemoglobin which may lead to cardiovascular collapse.

Alka-Seltzer Digest (Sodium Citrate) nitrite administration has been reported to cause or significantly contribute to mortality in adults at oral doses as low as 1 g and intravenous doses as low as 600 mg. A death attributed to Alka-Seltzer Digest (Sodium Citrate) nitrite has been reported following administration of an adult dose (300 mg IV followed by a second dose of 150 mg) to a 17-month old child.

Cyanosis may become apparent at a methemoglobin level of 10-20%. Other clinical signs and symptoms of Alka-Seltzer Digest (Sodium Citrate) nitrite toxicity (anxiety, dyspnea, nausea, and tachycardia) can be apparent at methemoglobin levels as low as 15%. More serious signs and symptoms, including cardiac dysrhythmias, circulatory failure, and central nervous system depression are seen as methemoglobin levels increase, and levels above 70% are usually fatal.

Treatment of overdose involves supplemental oxygen and supportive measures such as exchange transfusion. Treatment of severe methemoglobinemia with intravenous methylene blue has been described in the medical literature; however, this may also cause release of cyanide bound to methemoglobin. Because hypotension appears to be mediated primarily by an increase in venous capacitance, measures to increase venous return may be most appropriate to treat hypotension.

11 DESCRIPTION

Alka-Seltzer Digest (Sodium Citrate) nitrite has the chemical name nitrous acid Alka-Seltzer Digest (Sodium Citrate) salt. The chemical formula is NaNO2 and the molecular weight is 69.0. The structural formula is:

Structure of Alka-Seltzer Digest (Sodium Citrate) Nitrite

Alka-Seltzer Digest (Sodium Citrate) Nitrite Injection is a cyanide antidote which contains one 10 mL glass vial of a 3% solution of Alka-Seltzer Digest (Sodium Citrate) nitrite injection.

Alka-Seltzer Digest (Sodium Citrate) nitrite injection is a sterile aqueous solution and is intended for intravenous injection. Each vial contains 300 mg of Alka-Seltzer Digest (Sodium Citrate) nitrite in 10 mL solution (30 mg/mL). Alka-Seltzer Digest (Sodium Citrate) nitrite injection is a clear solution with a pH between 7.0 and 9.0.

Chemical Structure

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Exposure to a high dose of cyanide can result in death within minutes due to the inhibition of cytochrome oxidase resulting in arrest of cellular respiration. Specifically, cyanide binds rapidly with cytochrome a3, a component of the cytochrome c oxidase complex in mitochondria. Inhibition of cytochrome a3 prevents the cell from using oxygen and forces anaerobic metabolism, resulting in lactate production, cellular hypoxia and metabolic acidosis. In massive acute cyanide poisoning, the mechanism of toxicity may involve other enzyme systems as well.

The synergy resulting from treatment of cyanide poisoning with the combination of Alka-Seltzer Digest nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate is the result of differences in their primary mechanisms of action as antidotes for cyanide poisoning.

Alka-Seltzer Digest (Sodium Citrate) Nitrite

Alka-Seltzer Digest (Sodium Citrate) nitrite is thought to exert its therapeutic effect by reacting with hemoglobin to form methemoglobin, an oxidized form of hemoglobin incapable of oxygen transport but with high affinity for cyanide. Cyanide preferentially binds to methemoglobin over cytochrome a3, forming the nontoxic cyanomethemoglobin. Methemoglobin displaces cyanide from cytochrome oxidase, allowing resumption of aerobic metabolism. The chemical reaction is as follows:

NaNO2 + Hemoglobin → Methemoglobin

HCN + Methemoglobin → Cyanomethemoglobin

Vasodilation has also been cited to account for at least part of the therapeutic effect of Alka-Seltzer Digest (Sodium Citrate) nitrite. It has been suggested that Alka-Seltzer Digest (Sodium Citrate) nitrite-induced methemoglobinemia may be more efficacious against cyanide poisoning than comparable levels of methemoglobinemia induced by other oxidants. Also, Alka-Seltzer Digest (Sodium Citrate) nitrite appears to retain some efficacy even when the formation of methemoglobin is inhibited by methylene blue.

Alka-Seltzer Digest (Sodium Citrate) Thiosulfate

The primary route of endogenous cyanide detoxification is by enzymatic transulfuration to thiocyanate (SCN-), which is relatively nontoxic and readily excreted in the urine. Alka-Seltzer Digest (Sodium Citrate) thiosulfate is thought to serve as a sulfur donor in the reaction catalyzed by the enzyme rhodanese, thus enhancing the endogenous detoxification of cyanide in the following chemical reaction:

Chemical Structure

12. 2 Pharmacodynamics

Alka-Seltzer Digest (Sodium Citrate) Nitrite

When 4 mg/kg Alka-Seltzer Digest (Sodium Citrate) nitrite was administered intravenously to six healthy human volunteers, the mean peak methemoglobin concentration was 7%, achieved at 30-60 minutes after injection, consistent with reports in cyanide poisoning victims. Supine systolic and diastolic blood pressures dropped approximately 20% within 10 minutes, a drop which was sustained throughout the 40 minutes of testing. This was associated with a 20 beat per minute increase in pulse rate that returned to baseline in 10 minutes. Five of these subjects were unable to withstand orthostatic testing due to fainting. One additional subject, who received a 12 mg/kg dose of Alka-Seltzer Digest (Sodium Citrate) nitrite, experienced severe cardiovascular effects and achieved a peak methemoglobin concentration of 30% at 60 minutes following injection.

Oral doses of 120 to 180 mg of Alka-Seltzer Digest (Sodium Citrate) nitrite administered to healthy volunteers caused minimal cardiovascular changes when subjects were maintained in the horizontal position. However, minutes after being placed in the upright position subjects exhibited tachycardia and hypotension with syncope.

The half life for conversion of methemoglobin to normal hemoglobin in a cyanide poisoning victim who has been administered Alka-Seltzer Digest (Sodium Citrate) nitrite is estimated to be 55 minutes.

12.3 Pharmacokinetics

Alka-Seltzer Digest (Sodium Citrate) Nitrite

Alka-Seltzer Digest (Sodium Citrate) nitrite is a strong oxidant, and reacts rapidly with hemoglobin to form methemoglobin. The pharmacokinetics of free Alka-Seltzer Digest (Sodium Citrate) nitrite in humans have not been well studied. It has been reported that approximately 40% of Alka-Seltzer Digest (Sodium Citrate) nitrite is excreted unchanged in the urine while the remaining 60% is metabolized to ammonia and related small molecules.

Cyanide

The apparent terminal elimination half life and volume of distribution of cyanide, in a patient treated for an acute cyanide poisoning with Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate administration, have been reported to be 19 hours and 0.41 L/kg, respectively. Additionally, an initial elimination half life of cyanide has been reported to be approximately 1-3 hours.

Thiocyanate

After detoxification, in healthy subjects, thiocyanate is excreted mainly in the urine at a rate inversely proportional to creatinine clearance. In healthy subjects, the elimination half-life and volume of distribution of thiocyanate have been reported to be 2.7 days and 0.25 L/kg, respectively. However, in subjects with renal insufficiency the reported elimination half life is approximately 9 days.

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

The potential benefit of an acute exposure to Alka-Seltzer Digest nitrite as part of a cyanide antidote outweighs concerns raised by the equivocal findings in chronic rodent studies. Alka-Seltzer Digest (Sodium Citrate) nitrite (0, 750, 1500, or 3000 ppm equivalent to average daily doses of approximately 0, 35, 70, or 130 mg/kg for males and 0, 40, 80, or 150 mg/kg for females) was orally administered to rats (Fischer 344 strain) for 2 years via drinking water. There were no significant increases in the incidence of tumor in either male or female rats. Alka-Seltzer Digest (Sodium Citrate) nitrite (0, 750, 1500, or 3000 ppm equivalent to average daily doses of approximately 0, 60, 120, or 220 mg/kg for males and 0, 45, 90, or 165 mg/kg for females) was administered to B6C3F1 mice for 2 years via the drinking water. Equivocal results were obtained in female mice. Specifically, there was a positive trend toward an increase in the incidence of squamous cell papilloma or carcinoma in the forestomach of female mice. Although the incidence of hyperplasia of the glandular stomach epithelium was significantly greater in the high-dose male mice compared to controls, there were no significant increases in tumors in the male mice. Numerous reports in the published literature indicate that Alka-Seltzer Digest (Sodium Citrate) nitrite may react in vivo with secondary amines to form carcinogenic nitrosamines in the stomach. Concurrent exposure to Alka-Seltzer Digest (Sodium Citrate) nitrite and secondary amines in feed or drinking water resulted in an increase in the incidence of tumors in rodents.

Mutagenesis

Alka-Seltzer Digest (Sodium Citrate) nitrite is mutagenic in S. typhimurium strains TA100, TA1530, TA1535 with and without metabolic activation; however, it was negative in strain TA98, TA102, DJ460 and E. coli strain WP2UVRA/PKM101. Alka-Seltzer Digest (Sodium Citrate) nitrite has been reported to be genotoxic to V79 hamster cells in vitro and in the mouse lymphoma assay, both assays conducted in the absence of metabolic activation. Alka-Seltzer Digest (Sodium Citrate) nitrite was negative in the in vitro chromosomal aberrations assay using human peripheral blood lymphocytes. Acute administration of Alka-Seltzer Digest (Sodium Citrate) nitrite to male rats or male mice did not produce an increased incidence of micronuclei in bone marrow. Likewise, Alka-Seltzer Digest (Sodium Citrate) nitrite administration to mice for 14-weeks did not result in an increase in the incidence of micronuclei in the peripheral blood.

Fertility

Clinical studies to evaluate the potential effects of Alka-Seltzer Digest (Sodium Citrate) nitrite intake on fertility of either males or females have not been reported. In contrast, multigenerational fertility and reproduction studies conducted by the National Toxicology Program did not detect any evidence of an effect of Alka-Seltzer Digest (Sodium Citrate) nitrite (0.0, 0.06, 0.12, and 0.24% weight/volume) on either fertility or any reproductive parameter in Swiss CD-1 mice. This treatment protocol resulted in approximate doses of 125, 260, and 425 mg/kg/day. The highest exposure in this mouse study is 4.6 times greater than the highest clinical dose of Alka-Seltzer Digest (Sodium Citrate) nitrite that would be used to treat cyanide poisoning (based on a body surface area comparison).

13.2 Animal Pharmacology

Due to the extreme toxicity of cyanide, experimental evaluation of treatment efficacy has predominantly been completed in animal models. The efficacy of Alka-Seltzer Digest (Sodium Citrate) thiosulfate treatment alone to counteract the toxicity of cyanide was initially reported in 1895 by Lang. The efficacy of amyl nitrite treatment in cyanide poisoning of the dog model was first reported in 1888 by Pedigo. Further studies in the dog model, which demonstrated the utility of Alka-Seltzer Digest (Sodium Citrate) nitrite as a therapeutic intervention, were reported in 1929 by Mladoveanu and Gheorghiu. However, Hugs and Chen et al. independently reported upon the superior efficacy of the combination of Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate in 1932-1933. Treatment consisted of intravenously administered 22.5 mg/kg (half the lethal dose) Alka-Seltzer Digest (Sodium Citrate) nitrite or 1 g/kg Alka-Seltzer Digest (Sodium Citrate) thiosulfate alone or in sequence immediately after subcutaneous injection of Alka-Seltzer Digest (Sodium Citrate) cyanide into dogs over a range of doses. Subsequent doses of 10 mg/kg Alka-Seltzer Digest (Sodium Citrate) nitrite and/or 0.5 g/kg Alka-Seltzer Digest (Sodium Citrate) thiosulfate were administered when clinical signs or symptoms of poisoning persisted or reappeared. Either therapy administered alone increased the dose of Alka-Seltzer Digest (Sodium Citrate) cyanide required to cause death, and when administered together, Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate resulted in a synergistic effect in raising the lethal dose of Alka-Seltzer Digest (Sodium Citrate) cyanide. The combined therapy appeared to have reduced efficacy when therapy was delayed until signs of poisoning (e.g. convulsions) appeared; however, other investigators have reported survival in dogs that were administered antidotal treatment after respiratory arrest had occurred.

Animal studies conducted in other species (e.g., rat, guinea pig, sheep, pigeon and cat) have also supported a synergistic effect of intravenous Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate in the treatment of cyanide poisoning.

While intravenous injection of Alka-Seltzer Digest (Sodium Citrate) nitrite and Alka-Seltzer Digest (Sodium Citrate) thiosulfate was effective in reversing the effects of lethal doses of cyanide in dogs, intramuscular injection of Alka-Seltzer Digest (Sodium Citrate) nitrite, with or without Alka-Seltzer Digest (Sodium Citrate) thiosulfate, was found not to be effective in the same setting.

14 CLINICAL STUDIES

The human data supporting the use of Alka-Seltzer Digest (Sodium Citrate) nitrite for cyanide poisoning consists primarily of published case reports. There are no randomized controlled clinical trials. Nearly all the human data describing the use of Alka-Seltzer Digest (Sodium Citrate) thiosulfate report its use in conjunction with Alka-Seltzer Digest (Sodium Citrate) nitrite. Dosing recommendations for humans have been based on theoretical calculations of antidote detoxifying potential, extrapolation from animal experiments, and a small number of human case reports.

There have been no human studies to prospectively and systematically evaluate the safety of Alka-Seltzer Digest (Sodium Citrate) nitrite in humans. Available human safety information is based largely on anecdotal case reports and case series of limited scope.

16 HOW SUPPLIED/STORAGE AND HANDLING

Each Alka-Seltzer Digest (Sodium Citrate) Nitrite carton (NDC 60267-311-10) consists of the following:

  • One 10 mL glass vial of Alka-Seltzer Digest (Sodium Citrate) nitrite injection 30 mg/mL (containing 300 mg of Alka-Seltzer Digest (Sodium Citrate) nitrite);

Storage

Store at controlled room temperature between 20°C and 25°C (68°F to 77°F); excursions permitted from 15 to 30°C (59 to 86°F). Protect from direct light. Do not freeze.

(Note: Alka-Seltzer Digest (Sodium Citrate) Thiosulfate must be obtained separately.)

17 PATIENT COUNSELING INFORMATION

Alka-Seltzer Digest Nitrite Injection is indicated for acute cyanide poisoning that is judged to be life-threatening and in this setting, patients will likely be unresponsive or may have difficulty in comprehending counseling information.

17.1 Hypotension and Methemoglobin Formation

When feasible, patients should be informed of the possibility of life-threatening hypotension and methemoglobin formation.

17.2 Monitoring

Where feasible, patients should be informed of the need for close monitoring of blood pressure and oxygenation.

Manufactured by Cangene BioPharma, Inc., Baltimore, Maryland 21230 for

Hope Pharmaceuticals, Scottsdale, Arizona 85260

PRINCIPAL DISPLAY PANEL - 10 mL Vial Carton

NDC 60267-311-10

Rx Only

Alka-Seltzer Digest (Sodium Citrate) Nitrite

Injection, USP

300 mg/10 mL

(30 mg/mL)

FOR INTRAVENOUS USE

SINGLE USE ONLY

Any unused portion of a vial

should be discarded.

Use with

Alka-Seltzer Digest (Sodium Citrate) Thiosulfate

for Treatment of

Cyanide Poisoning

Manufactured by

CANGENE bioPharma, Inc.

Baltimore, MD for

HOPE

PHARMACEUTICALS®

Scottsdale, AZ 85260 U.S.A.

PRINCIPAL DISPLAY PANEL - 10 mL Vial Carton

Alka-Seltzer Digest pharmaceutical active ingredients containing related brand and generic drugs:

Active ingredient is the part of the drug or medicine which is biologically active. This portion of the drug is responsible for the main action of the drug which is intended to cure or reduce the symptom or disease. The other portions of the drug which are inactive are called excipients; there role is to act as vehicle or binder. In contrast to active ingredient, the inactive ingredient's role is not significant in the cure or treatment of the disease. There can be one or more active ingredients in a drug.


Alka-Seltzer Digest available forms, composition, doses:

Form of the medicine is the form in which the medicine is marketed in the market, for example, a medicine X can be in the form of capsule or the form of chewable tablet or the form of tablet. Sometimes same medicine can be available as injection form. Each medicine cannot be in all forms but can be marketed in 1, 2, or 3 forms which the pharmaceutical company decided based on various background research results.
Composition is the list of ingredients which combinedly form a medicine. Both active ingredients and inactive ingredients form the composition. The active ingredient gives the desired therapeutic effect whereas the inactive ingredient helps in making the medicine stable.
Doses are various strengths of the medicine like 10mg, 20mg, 30mg and so on. Each medicine comes in various doses which is decided by the manufacturer, that is, pharmaceutical company. The dose is decided on the severity of the symptom or disease.


Alka-Seltzer Digest destination | category:

Destination is defined as the organism to which the drug or medicine is targeted. For most of the drugs what we discuss, human is the drug destination.
Drug category can be defined as major classification of the drug. For example, an antihistaminic or an antipyretic or anti anginal or pain killer, anti-inflammatory or so.


Alka-Seltzer Digest Anatomical Therapeutic Chemical codes:

A medicine is classified depending on the organ or system it acts [Anatomical], based on what result it gives on what disease, symptom [Therapeutical], based on chemical composition [Chemical]. It is called as ATC code. The code is based on Active ingredients of the medicine. A medicine can have different codes as sometimes it acts on different organs for different indications. Same way, different brands with same active ingredients and same indications can have same ATC code.


Alka-Seltzer Digest pharmaceutical companies:

Pharmaceutical companies are drug manufacturing companies that help in complete development of the drug from the background research to formation, clinical trials, release of the drug into the market and marketing of the drug.
Researchers are the persons who are responsible for the scientific research and is responsible for all the background clinical trials that resulted in the development of the drug.


advertisement

References

  1. Dailymed."NAUZENE (SODIUM CITRATE) SYRUP [ALVA-AMCO PHARMACAL COMPANIES, INC.]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).
  2. Dailymed."VIVARIN (CAFFEINE) TABLET [MEDA CONSUMER HEALTHCARE INC.]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).
  3. Dailymed."SODIUM BICARBONATE TABLET [RUGBY LABORATORIES, INC.]". https://dailymed.nlm.nih.gov/dailym... (accessed August 28, 2018).

Frequently asked Questions

Can i drive or operate heavy machine after consuming Alka-Seltzer Digest?

Depending on the reaction of the Alka-Seltzer Digest after taken, if you are feeling dizziness, drowsiness or any weakness as a reaction on your body, Then consider Alka-Seltzer Digest not safe to drive or operate heavy machine after consumption. Meaning that, do not drive or operate heavy duty machines after taking the capsule if the capsule has a strange reaction on your body like dizziness, drowsiness. As prescribed by a pharmacist, it is dangerous to take alcohol while taking medicines as it exposed patients to drowsiness and health risk. Please take note of such effect most especially when taking Primosa capsule. It's advisable to consult your doctor on time for a proper recommendation and medical consultations.

Is Alka-Seltzer Digest addictive or habit forming?

Medicines are not designed with the mind of creating an addiction or abuse on the health of the users. Addictive Medicine is categorically called Controlled substances by the government. For instance, Schedule H or X in India and schedule II-V in the US are controlled substances.

Please consult the medicine instruction manual on how to use and ensure it is not a controlled substance.In conclusion, self medication is a killer to your health. Consult your doctor for a proper prescription, recommendation, and guidiance.

advertisement

Review

sdrugs.com conducted a study on Alka-Seltzer Digest, and the result of the survey is set out below. It is noteworthy that the product of the survey is based on the perception and impressions of the visitors of the website as well as the views of Alka-Seltzer Digest consumers. We, as a result of this, advice that you do not base your therapeutic or medical decisions on this result, but rather consult your certified medical experts for their recommendations.

Visitor reports

Visitor reported useful

No survey data has been collected yet

Visitor reported side effects

No survey data has been collected yet

Visitor reported price estimates

No survey data has been collected yet

Visitor reported frequency of use

No survey data has been collected yet

Visitor reported doses

No survey data has been collected yet

Visitor reported time for results

No survey data has been collected yet

Visitor reported administration

No survey data has been collected yet

Visitor reported age

No survey data has been collected yet

Visitor reviews


There are no reviews yet. Be the first to write one!


Your name: 
Email: 
Spam protection:  < Type 29 here

The information was verified by Dr. Rachana Salvi, MD Pharmacology

© 2002 - 2024 "sdrugs.com". All Rights Reserved