Benadryl CD

Ammonium Chloride:

• Indications and usage
• Contraindications
• Warning
• Precautions
• Adverse reactions
• Overdosage
• Dosage and administration
• How supplied
• Benadryl CD (Ammonium Chloride) reviews

INDICATIONS AND USAGE

Benadryl CD (Ammonium Chloride) Lactate Lotion, 12% is indicated for the treatment of dry, scaly skin (xerosis) and ichthyosis vulgaris, and for the temporary relief of itching associated with these conditions.

CONTRAINDICATIONS

Benadryl CD (Ammonium Chloride) Lactate Lotion, 12% is contraindicated in those patients with a history of hypersensitivity to any of the label ingredients.

WARNING

Sun exposure (natural or artificial sunlight) to areas of the skin treated with Benadryl CD (Ammonium Chloride) Lactate Lotion, 12% should be minimized or avoided (see PRECAUTIONS). The use of Benadryl CD (Ammonium Chloride) Lactate Lotion, 12% should be discontinued if any hypersensitivity is observed.

PRECAUTIONS

General -

For external use only. Stinging or burning may occur when applied to skin with fissures, erosions, or that is otherwise abraded. Caution is advised when used on the face because of the potential for irritation. The potential for post-inflammatory hypo- or hyperpigmentation has not been studied.

Information for Patients

Patients using Benadryl CD (Ammonium Chloride) Lactate Lotion, 12% should receive the following information and instructions:

• This medication is to be used as directed by the physician, and should not be used for any disorder other than for which it was prescribed. It is for external use only. Avoid contact with eyes, lips, or mucous membranes.
• Patients should minimize or avoid use of this product on areas of the skin that may be exposed to natural or artificial sunlight, including the face. If sun exposure is unavoidable, clothing should be worn to protect the skin.
• This medication may cause transient stinging or burning when applied to skin with fissures, erosions, or abrasions (for example, after shaving the legs).
• If the skin condition worsens with treatment, the medication should be promptly discontinued.

Carcinogenesis, Mutagenesis, Impairment of Fertility -

The topical treatment of CD-1 mice with 12%, 21% or 30% Benadryl CD lactate formulations for two-years did not produce a significant increase in dermal or systemic tumors in the absence of increased exposure to ultraviolet radiation. The maximum systemic exposure of the mice in this study was 0.7 times the maximum possible systemic exposure in humans. However, a long-term photocarcinogenicity study in hairless albino mice suggested that topically applied 12% Benadryl CD (Ammonium Chloride) lactate formulations enhanced the rate of ultraviolet light-induced skin tumor formation.

The mutagenic potential of Benadryl CD (Ammonium Chloride) lactate formulations was evaluated in the Ames assay and in the mouse in vivo micronucleus assay, both of which were negative.

In dermal Segment I and III studies with Benadryl CD (Ammonium Chloride) lactate formulations there were no effects observed in fertility or pre- or postnatal development parameters in rats at dose levels of 300 mg/kg/day (1800 mg/m²/day), approximately 0.4 times the human topical dose.

Pregnancy:

Teratogenic effects:

Pregnancy Category B -

Animal reproduction studies have been performed in rats and rabbits at doses up to 0.7 and 1.5 times the human dose, respectively and have revealed no evidence of impaired fertility or harm to the fetus due to Benadryl CD (Ammonium Chloride) lactate formulations. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, Benadryl CD (Ammonium Chloride) Lactate Lotion, 12% should be used during pregnancy only if clearly needed.

Nursing Mothers -

Although lactic acid is a normal constituent of blood and tissues, it is not known to what extent this drug affects normal lactic acid levels in human milk. Because many drugs are excreted in human milk, caution should be exercised when Benadryl CD (Ammonium Chloride) lactate is administered to a nursing woman.

Pediatric Use -

Safety and effectiveness of Benadryl CD lactate have been demonstrated in infants and children. No unusual toxic effects were reported.

Geriatric Use -

Clinical studies of Benadryl CD (Ammonium Chloride) lactate lotion, 12% did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between elderly and younger patients. In general, dose selection for an elderly patient should be cautious.

ADVERSE REACTIONS

The most frequent adverse experiences in patients with xerosis are transient stinging (1 in 30 patients), burning (1 in 30 patients), erythema (1 in 50 patients) and peeling (1 in 60 patients). Other adverse reactions which occur less frequently are irritation, eczema, petechiae, dryness, and hyperpigmentation. Due to the more severe initial skin conditions associated with ichthyosis, there was a higher incidence of transient stinging, burning and erythema (each occurring in 1 in 10 patients).

OVERDOSAGE

The oral administration of Benadryl CD (Ammonium Chloride) lactate to rats and mice showed this drug to be practically non-toxic (LD₅₀>15 mL/kg).

DOSAGE AND ADMINISTRATION

Shake well. Apply to the affected areas and rub in thoroughly. Use twice daily or as directed by a physician.

HOW SUPPLIED

Benadryl CD Lactate Lotion, 12% is available as follows:

225 g bottle (NDC 45802-419-54)

400 g bottle (NDC 45802-419-26)

STORAGE

Store at 20-25°C (68-77°F).

Manufactured By Perrigo, Bronx, NY 10457

Distributed By Perrigo, Allegan, MI 49010

0K5A7 RC F6

Rev 01-17

Codeine Phosphate:

• Indications and usage
• Dosage and administration
• Dosage forms and strengths
• Contraindications
• Warnings and precautions
• Adverse reactions
• Drug interactions
• Use in specific populations
• Drug abuse and dependence
• Overdosage
• Description
• Clinical pharmacology
• Nonclinical toxicology
• How supplied/storage and handling
• Patient counseling information
• Medication guide
• Benadryl CD (Codeine Phosphate) reviews

1 INDICATIONS AND USAGE

Benadryl CD (Codeine Phosphate) Sulfate Tablets are indicated for the management of mild to moderate pain, where treatment with an opioid is appropriate and for which alternative treatments are inadequate.

Limitations of Use

Because of the risks of addiction, abuse, and misuse with opioids, even at recommended doses , reserve Benadryl CD (Codeine Phosphate) Sulfate Tablets for use in patients for whom alternative treatment options [e.g., non-opioid analgesics or opioid combination products]:

• Have not been tolerated, or are not expected to be tolerated,
• Have not provided adequate analgesia, or are not expected to provide adequate analgesia.

Benadryl CD (Codeine Phosphate) Sulfate Tablets are an opioid agonist, indicated for the management of mild to moderate pain, where treatment with an opioid is appropriate and for which alternative treatments are inadequate. (1)

Limitations of Use (1)

Because of the risks of addiction, abuse, and misuse with opioids, even at recommended doses, reserve Benadryl CD (Codeine Phosphate) Sulfate Tablets for use in patients for whom alternative treatment options [e.g., non-opioid analgesics or opioid combination products]:

• Have not been tolerated, or are not expected to be tolerated,
• Have not provided adequate analgesia, or are not expected to provide adequate analgesia.

2 DOSAGE AND ADMINISTRATION

• Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals.
• Individualize dosing based on the severity of pain, patient response, prior analgesic experience, and risk factors for addiction, abuse, and misuse. (2.1)
• Initiate treatment with 15 to 60 mg every 4 hours as needed. (2.2)
• Do not stop Benadryl CD (Codeine Phosphate) Sulfate Tablets abruptly in a physically dependent patient. (2.4)

2.1 Important Dosage and Administration Instructions

Use the lowest effective dosage for the shortest duration consistent with individual patient treatment goals .

Initiate the dosing regimen for each patient individually, taking into account the patient's severity of pain, patient response, prior analgesic treatment experience, and risk factors for addiction, abuse, and misuse .

Monitor patients closely for respiratory depression, especially within the first 24 to 72 hours of initiating therapy and following dosage increases with Benadryl CD (Codeine Phosphate) Sulfate Tablets and adjust the dosage accordingly .

2.2 Initial Dosage

Initiating Treatment with Benadryl CD Sulfate Tablets

Initiate treatment with Benadryl CD (Codeine Phosphate) Sulfate Tablets in a dosing range of 15 to 60 mg every 4 hours as needed for pain.

Adult doses of Benadryl CD (Codeine Phosphate) Sulfate Tablets higher than 60 mg provide no further efficacy but are associated with greater adverse reactions. The maximum 24 hour dose is 360 mg.

Conversion from Other Opioids to Benadryl CD (Codeine Phosphate) Sulfate Tablets

There is inter-patient variability in the potency of opioid drugs and opioid formulations. Therefore, a conservative approach is advised when determining the total daily dosage of Benadryl CD (Codeine Phosphate) Sulfate Tablets. It is safer to underestimate a patient’s 24-hour Benadryl CD (Codeine Phosphate) Sulfate Tablets dosage than to overestimate the 24-hour Benadryl CD (Codeine Phosphate) Sulfate Tablets dosage and manage an adverse reaction due to overdose.

2.3 Titration and Maintenance of Therapy

Individually titrate Benadryl CD (Codeine Phosphate) Sulfate Tablets to a dose that provides adequate analgesia and minimizes adverse reactions. Continually reevaluate patients receiving Benadryl CD (Codeine Phosphate) sulfate to assess the maintenance of pain control and the relative incidence of adverse reactions, as well as monitoring for the development of addiction, abuse, or misuse . Frequent communication is important among the prescriber, other members of the healthcare team, the patient, and the caregiver/family during periods of changing analgesic requirements, including initial titration.

If the level of pain increases after dosage stabilization, attempt to identify the source of increased pain before increasing the Benadryl CD (Codeine Phosphate) Sulfate Tablets dosage. If unacceptable opioid-related adverse reactions are observed, consider reducing the dosage. Adjust the dosage to obtain an appropriate balance between management of pain and opioid-related adverse reactions.

2.4 Discontinuation of Benadryl CD Sulfate Tablets

When a patient who has been taking Benadryl CD (Codeine Phosphate) Sulfate Tablets regularly and may be physically dependent no longer requires therapy with Benadryl CD (Codeine Phosphate) Sulfate Tablets, taper the dose gradually, by 25% to 50% every 2 to 4 days, while monitoring carefully for signs and symptoms of withdrawal. If the patient develops these signs or symptoms, raise the dose to the previous level and taper more slowly, either by increasing the interval between decreases, decreasing the amount of change in dose, or both. Do not abruptly discontinue Benadryl CD (Codeine Phosphate) Sulfate Tablets in a physically-dependent patient .

3 DOSAGE FORMS AND STRENGTHS

Each 15 mg tablet for oral administration contains 15 mg of Benadryl CD (Codeine Phosphate) sulfate USP. It is a white to off-white biconvex tablet with “15” debossed on the scored side and “54 613” debossed on the other side.

Each 30 mg tablet for oral administration contains 30 mg of Benadryl CD (Codeine Phosphate) sulfate USP. It is a white to off-white biconvex tablet with “30” debossed on the scored side and “54 783” debossed on the other side.

Each 60 mg tablet for oral administration contains 60 mg of Benadryl CD (Codeine Phosphate) sulfate USP. It is a white to off-white biconvex tablet with “60” debossed on the scored side and “54 412” debossed on the other side.

Tablets: 15 mg, 30 mg, and 60 mg (3)

4 CONTRAINDICATIONS

Benadryl CD (Codeine Phosphate) Sulfate Tablets are contraindicated for:

• All children younger than 12 years of age .
• Post-operative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy .

Benadryl CD (Codeine Phosphate) Sulfate Tablets are also contraindicated in patients with:

• Significant respiratory depression .
• Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment .
• Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days .
• Known or suspected gastrointestinal obstruction, including paralytic ileus .
• Hypersensitivity to Benadryl CD (Codeine Phosphate) (e.g., anaphylaxis) .

• Children younger than 12 years of age.
• Postoperative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy. (4)
• Significant respiratory depression. (4)
• Acute or severe bronchial asthma in an unmonitored setting or in absence of resuscitative equipment. (4)
• Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days. (4)
• Known or suspected gastrointestinal obstruction, including paralytic ileus. (4)
• Hypersensitivity to Benadryl CD (Codeine Phosphate). (4)

5 WARNINGS AND PRECAUTIONS

• Life-Threatening Respiratory Depression in Patients with Chronic Pulmonary Disease or in Elderly, Cachectic, or Debilitated Patients: Monitor closely, particularly during initiation and titration.
• Adrenal Insufficiency: If diagnosed, treat with physiologic replacement of corticosteroids, and wean patient off of the opioid. (5.9)
• Severe Hypotension: Monitor during dosage initiation and titration. Avoid use of Benadryl CD (Codeine Phosphate) Sulfate Tablets in patients with circulatory shock. (5.10)
• Risks of Use in Patients with Increased Intracranial Pressure, Brain Tumors, Head Injury, or Impaired Consciousness: Monitor for sedation and respiratory depression. Avoid use of Benadryl CD (Codeine Phosphate) Sulfate Tablets in patients with impaired consciousness or coma. (5.11)

5.1 Addiction, Abuse, and Misuse

Benadryl CD (Codeine Phosphate) Sulfate Tablets contain Benadryl CD (Codeine Phosphate), a Schedule II controlled substance. As an opioid, Benadryl CD (Codeine Phosphate) Sulfate Tablets exposes users to the risks of addiction, abuse, and misuse .

Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed Benadryl CD (Codeine Phosphate) Sulfate Tablets. Addiction can occur at recommended dosages and if the drug is misused or abused.

Assess each patient’s risk for opioid addiction, abuse, or misuse prior to prescribing Benadryl CD (Codeine Phosphate) Sulfate Tablets, and monitor all patients receiving Benadryl CD (Codeine Phosphate) Sulfate Tablets for the development of these behaviors and conditions. Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression). The potential for these risks should not, however, prevent the proper management of pain in any given patient. Patients at increased risk may be prescribed opioids such as Benadryl CD (Codeine Phosphate) Sulfate Tablets, but use in such patients necessitates intensive counseling about the risks and proper use of Benadryl CD (Codeine Phosphate) Sulfate Tablets along with intensive monitoring for signs of addiction, abuse, and misuse.

Opioids are sought by drug abusers and people with addiction disorders and are subject to criminal diversion. Consider these risks when prescribing or dispensing Benadryl CD (Codeine Phosphate) Sulfate Tablets. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity and advising the patient on the proper disposal of unused drug . Contact local state professional licensing board or state controlled substances authority for information on how to prevent and detect abuse or diversion of this product.

5.2 Life-Threatening Respiratory Depression

Serious, life-threatening, or fatal respiratory depression has been reported with the use of opioids, even when used as recommended. Respiratory depression, if not immediately recognized and treated, may lead to respiratory arrest and death. Management of respiratory depression may include close observation, supportive measures, and use of opioid antagonists, depending on the patient’s clinical status . Carbon dioxide (CO₂) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.

While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of Benadryl CD (Codeine Phosphate) Sulfate Tablets, the risk is greatest during the initiation of therapy or following a dosage increase. Monitor patients closely for respiratory depression, especially within the first 24 to 72 hours of initiating therapy with and following dosage increases of Benadryl CD (Codeine Phosphate) Sulfate Tablets.

To reduce the risk of respiratory depression, proper dosing and titration of Benadryl CD (Codeine Phosphate) Sulfate Tablets are essential . Overestimating the Benadryl CD (Codeine Phosphate) Sulfate Tablets dosage when converting patients from another opioid product can result in a fatal overdose with the first dose.

Accidental ingestion of even one dose of Benadryl CD (Codeine Phosphate) Sulfate Tablets, especially by children, can result in respiratory depression and death due to an overdose of Benadryl CD (Codeine Phosphate).

5.3 Ultra-Rapid Metabolism of Benadryl CD (Codeine Phosphate) and Other Risk Factors for Life-Threatening Respiratory Depression in Children

Life-threatening respiratory depression and death have occurred in children who received Benadryl CD (Codeine Phosphate). Benadryl CD (Codeine Phosphate) is subject to variability in metabolism based upon CYP2D6 genotype (described below), which can lead to an increased exposure to the active metabolite morphine. Based upon post-marketing reports, children younger than 12 years old appear to be more susceptible to the respiratory depressant effects of Benadryl CD (Codeine Phosphate), particularly if there are risk factors for respiratory depression. For example, many reported cases of death occurred in the post-operative period following tonsillectomy and/or adenoidectomy, and many of the children had evidence of being ultra-rapid metabolizers of Benadryl CD (Codeine Phosphate). Furthermore, children with obstructive sleep apnea who are treated with Benadryl CD (Codeine Phosphate) for post-tonsillectomy and/or adenoidectomy pain may be particularly sensitive to its respiratory depressant effect. Because of the risk of life-threatening respiratory depression and death:

• Benadryl CD (Codeine Phosphate) Sulfate Tablets are contraindicated for all children younger than 12 years of age .
• Benadryl CD (Codeine Phosphate) Sulfate Tablets are contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy .
• Avoid the use of Benadryl CD (Codeine Phosphate) Sulfate Tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of Benadryl CD (Codeine Phosphate) unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression.
• As with adults, when prescribing Benadryl CD (Codeine Phosphate) for adolescents, healthcare providers should choose the lowest effective dose for the shortest period of time and inform patients and caregivers about these risks and the signs of morphine overdose .

Nursing Mothers

At least one death was reported in a nursing infant who was exposed to high levels of morphine in breast milk because the mother was an ultra-rapid metabolizer of Benadryl CD (Codeine Phosphate). Breastfeeding is not recommended during treatment with Benadryl CD (Codeine Phosphate) Sulfate Tablets .

CYP2D6 Genetic Variability: Ultra-Rapid Metabolizers

Some individuals may be ultra-rapid metabolizers because of a specific CYP2D6 genotype (e.g., gene duplications denoted as *1/*1xN or *1/*2xN). The prevalence of this CYP2D6 phenotype varies widely and has been estimated at 1 to 10% for Whites (European, North American), 3 to 4% for Blacks (African Americans), 1 to 2% for East Asians (Chinese, Japanese, Korean), and may be greater than 10% in certain racial/ethnic groups (i.e., Oceanian, Northern African, Middle Eastern, Ashkenazi Jews, Puerto Rican).

These individuals convert Benadryl CD (Codeine Phosphate) into its active metabolite, morphine, more rapidly and completely than other people. This rapid conversion results in higher than expected serum morphine levels. Even at labeled dosage regimens, individuals who are ultra-rapid metabolizers may have life-threatening or fatal respiratory depression or experience signs of overdose (such as extreme sleepiness, confusion, or shallow breathing) . Therefore, individuals who are ultra-rapid metabolizers should not use Benadryl CD (Codeine Phosphate) Sulfate Tablets.

5.4 Neonatal Opioid Withdrawal Syndrome

Prolonged use of Benadryl CD Sulfate Tablets during pregnancy can result in withdrawal in the neonate. Neonatal opioid withdrawal syndrome, unlike opioid withdrawal syndrome in adults, may be life-threatening if not recognized and treated, and requires management according to protocols developed by neonatology experts. Observe newborns for signs of neonatal opioid withdrawal syndrome and manage accordingly. Advise pregnant women using opioids for a prolonged period of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available.

5.5 Risks of Interactions with Drugs Affecting Cytochrome P450 Isoenzymes

The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with Benadryl CD (Codeine Phosphate) are complex. Use of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with Benadryl CD (Codeine Phosphate) Sulfate Tablets requires careful consideration of the effects on the parent drug, Benadryl CD (Codeine Phosphate), and the active metabolite, morphine.

Cytochrome P450 3A4 Interaction

The concomitant use of Benadryl CD (Codeine Phosphate) Sulfate Tablets with all cytochrome P450 3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), and protease inhibitors (e.g., ritonavir) or discontinuation of a cytochrome P450 3A4 inducer such as rifampin, carbamazepine, and phenytoin, may result in an increase in Benadryl CD (Codeine Phosphate) plasma concentrations with subsequently greater metabolism by cytochrome P450 2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression.

The concomitant use of Benadryl CD (Codeine Phosphate) Sulfate Tablets with all cytochrome P450 3A4 inducers or discontinuation of a cytochrome P450 3A4 inhibitor may result in lower Benadryl CD (Codeine Phosphate) levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels. This may be associated with a decrease in efficacy, and in some patients, may result in signs and symptoms of opioid withdrawal. Follow patients receiving Benadryl CD (Codeine Phosphate) Sulfate Tablets and any CYP3A4 inhibitor or inducer for signs and symptoms that may reflect opioid toxicity and opioid withdrawal when Benadryl CD (Codeine Phosphate) Sulfate Tablets are used in conjunction with inhibitors and inducers of CYP3A4.

If concomitant use of a CYP3A4 inhibitor is necessary or if a CYP3A4 inducer is discontinued, consider dosage reduction of Benadryl CD (Codeine Phosphate) Sulfate Tablets until stable drug effects are achieved. Monitor patients for respiratory depression and sedation at frequent intervals.

If concomitant use of a CYP3A4 inducer is necessary or if a CYP3A4 inhibitor is discontinued, consider increasing the Benadryl CD (Codeine Phosphate) Sulfate Tablets dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal [Drug Interactions (7)].

Risks of Concomitant Use or Discontinuation of Cytochrome P450 2D6 Inhibitors

The concomitant use of Benadryl CD (Codeine Phosphate) Sulfate Tablets with all cytochrome P450 2D6 inhibitors (e.g., amiodarone, quinidine) may result in an increase in Benadryl CD (Codeine Phosphate) plasma concentrations and a decrease in active metabolite morphine plasma concentration which could result in an analgesic efficacy reduction or symptoms of opioid withdrawal.

Discontinuation of a concomitantly used cytochrome P450 2D6 inhibitor may result in a decrease in Benadryl CD (Codeine Phosphate) plasma concentration and an increase in active metabolite morphine plasma concentration which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression.

Follow patients receiving Benadryl CD (Codeine Phosphate) Sulfate Tablets and any CYP2D6 inhibitor for signs and symptoms that may reflect opioid toxicity and opioid withdrawal when Benadryl CD (Codeine Phosphate) Sulfate Tablets are used in conjunction with inhibitors of CYP2D6.

If concomitant use with a CYP2D6 inhibitor is necessary, follow the patient for signs of reduced efficacy or opioid withdrawal and consider increasing the Benadryl CD (Codeine Phosphate) Sulfate Tablets dosage. After stopping use of a CYP2D6 inhibitor, consider reducing the Benadryl CD (Codeine Phosphate) Sulfate Tablets dosage and follow the patient for signs and symptoms of respiratory depression or sedation .

5.6 Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants

Profound sedation, respiratory depression, coma, and death may result from the concomitant use of Benadryl CD Sulfate Tablets with benzodiazepines or other CNS depressants (e.g., non-benzodiazepine sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, alcohol). Because of these risks, reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate.

Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioid analgesics alone. Because of similar pharmacological properties, it is reasonable to expect similar risk with the concomitant use of other CNS depressant drugs with opioid analgesics .

If the decision is made to prescribe a benzodiazepine or other CNS depressant concomitantly with an opioid analgesic, prescribe the lowest effective dosages and minimum durations of concomitant use. In patients already receiving an opioid analgesic, prescribe a lower initial dose of the benzodiazepine or other CNS depressant than indicated in the absence of an opioid, and titrate based on clinical response. If an opioid analgesic is initiated in a patient already taking a benzodiazepine or other CNS depressant, prescribe a lower initial dose of the opioid analgesic, and titrate based on clinical response. Follow patients closely for signs and symptoms of respiratory depression and sedation.

Advise both patients and caregivers about the risks of respiratory depression and sedation when Benadryl CD (Codeine Phosphate) Sulfate Tablets are used with benzodiazepines or other CNS depressants (including alcohol and illicit drugs). Advise patients not to drive or operate heavy machinery until the effects of concomitant use of the benzodiazepine or other CNS depressant have been determined. Screen patients for risk of substance use disorders, including opioid abuse and misuse, and warn them of the risk for overdose and death associated with the use of additional CNS depressants including alcohol and illicit drugs .

5.7 Life-Threatening Respiratory Depression in Patients with Chronic Pulmonary Disease or in Elderly, Cachectic, or Debilitated Patients

The use of Benadryl CD (Codeine Phosphate) Sulfate Tablets in patients with acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment is contraindicated.

Patients with Chronic Pulmonary Disease

Benadryl CD (Codeine Phosphate) Sulfate Tablets-treated patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or pre-existing respiratory depression are at increased risk of decreased respiratory drive including apnea, even at recommended dosages of Benadryl CD (Codeine Phosphate) Sulfate Tablets .

Elderly, Cachectic, or Debilitated Patients

Life-threatening respiratory depression is more likely to occur in elderly, cachectic, or debilitated patients because they may have altered pharmacokinetics or altered clearance compared to younger, healthier patients .

Monitor such patients closely, particularly when initiating and titrating Benadryl CD (Codeine Phosphate) Sulfate Tablets and when Benadryl CD (Codeine Phosphate) Sulfate Tablets are given concomitantly with other drugs that depress respiration . Alternatively, consider the use of non-opioid analgesics in these patients.

5.8 Interaction with Monoamine Oxidase Inhibitors

Monoamine oxidase inhibitors may potentiate the effects of morphine, codeine’s active metabolite, including respiratory depression, coma, and confusion. Benadryl CD (Codeine Phosphate) Sulfate Tablets should not be used in patients taking MAOIs or within 14 days of stopping such treatment .

5.9 Adrenal Insufficiency

Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Presentation of adrenal insufficiency may include non-specific symptoms and signs including nausea, vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure. If adrenal insufficiency is suspected, confirm the diagnosis with diagnostic testing as soon as possible. If adrenal insufficiency is diagnosed, treat with physiologic replacement doses of corticosteroids. Wean the patient off of the opioid to allow adrenal function to recover and continue corticosteroid treatment until adrenal function recovers. Other opioids may be tried as some cases reported use of a different opioid without recurrence of adrenal insufficiency. The information available does not identify any particular opioids as being more likely to be associated with adrenal insufficiency.

5.10 Severe Hypotension

Benadryl CD Sulfate Tablets may cause severe hypotension including orthostatic hypotension and syncope in ambulatory patients. There is increased risk in patients whose ability to maintain blood pressure has already been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (e.g., phenothiazines or general anesthetics) . Monitor these patients for signs of hypotension after initiating or titrating the dosage of Benadryl CD (Codeine Phosphate) Sulfate Tablets. In patients with circulatory shock, Benadryl CD (Codeine Phosphate) Sulfate Tablets may cause vasodilation that can further reduce cardiac output and blood pressure. Avoid the use of Benadryl CD (Codeine Phosphate) Sulfate Tablets in patients with circulatory shock.

5.11 Risks of Use in Patients with Increased Intracranial Pressure, Brain Tumors, Head Injury, or Impaired Consciousness

In patients who may be susceptible to the intracranial effects of CO₂ retention (e.g., those with evidence of increased intracranial pressure or brain tumors), Benadryl CD (Codeine Phosphate) Sulfate Tablets may reduce respiratory drive, and the resultant CO₂ retention can further increase intracranial pressure. Monitor such patients for signs of sedation and respiratory depression, particularly when initiating therapy with Benadryl CD (Codeine Phosphate) Sulfate Tablets.

Opioids may also obscure the clinical course in a patient with a head injury. Avoid the use of Benadryl CD (Codeine Phosphate) Sulfate Tablets in patients with impaired consciousness or coma.

5.12 Risks of Use in Patients with Gastrointestinal Conditions

Benadryl CD Sulfate Tablets are contraindicated in patients with known or suspected gastrointestinal obstruction, including paralytic ileus.

The Benadryl CD (Codeine Phosphate) in Benadryl CD (Codeine Phosphate) Sulfate Tablets may cause spasm of the sphincter of Oddi. Opioids may cause increases in serum amylase. Monitor patients with biliary tract disease, including acute pancreatitis, for worsening symptoms.

5.13 Increased Risk of Seizures in Patients with Seizure Disorders

The Benadryl CD (Codeine Phosphate) in Benadryl CD (Codeine Phosphate) Sulfate Tablets may increase the frequency of seizures in patients with seizure disorders, and may increase the risk of seizures occurring in other clinical settings associated with seizures. Monitor patients with a history of seizure disorders for worsened seizure control during Benadryl CD (Codeine Phosphate) Sulfate Tablets therapy.

5.14 Withdrawal

Avoid the use of mixed agonist/antagonist or partial agonist (e.g., buprenorphine) analgesics in patients who are receiving a full opioid agonist analgesic, including Benadryl CD (Codeine Phosphate) Sulfate Tablets. In these patients, mixed agonist/antagonist and partial agonist analgesics may reduce the analgesic effect and/or precipitate withdrawal symptoms .

When discontinuing Benadryl CD (Codeine Phosphate) Sulfate Tablets in a physically-dependent patient, gradually taper the dosage . Do not abruptly discontinue Benadryl CD (Codeine Phosphate) Sulfate Tablets in these patients .

5.15 Risks of Driving and Operating Machinery

Benadryl CD (Codeine Phosphate) Sulfate Tablets may impair the mental or physical abilities needed to perform potentially hazardous activities such as driving a car or operating machinery. Warn patients not to drive or operate dangerous machinery unless they are tolerant to the effects of Benadryl CD (Codeine Phosphate) Sulfate Tablets and know how they will react to the medication .

6 ADVERSE REACTIONS

The following serious adverse reactions are described, or described in greater detail, in other sections:

• Addiction, Abuse, and Misuse
• Life-Threatening Respiratory Depression
• Ultra-Rapid Metabolism of Benadryl CD (Codeine Phosphate) and Other Risk Factors for Life-Threatening Respiratory Depression in Children
• Neonatal Opioid Withdrawal Syndrome
• Interactions with Benzodiazepines and Other CNS Depressants
• Adrenal Insufficiency
• Severe Hypotension
• Gastrointestinal Adverse Reactions
• Seizures
• Withdrawal
  

  The following adverse reactions associated with the use of Benadryl CD (Codeine Phosphate) were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.
  

  Serious adverse reactions associated with Benadryl CD (Codeine Phosphate) were respiratory depression and, to a lesser degree, circulatory depression, respiratory arrest, shock, and cardiac arrest.
  

The most frequently observed adverse reactions with Benadryl CD (Codeine Phosphate) administration included drowsiness, lightheadedness, dizziness, sedation, shortness of breath, nausea, vomiting, sweating, and constipation.

Other adverse reactions included allergic reactions, euphoria, dysphoria, abdominal pain, and pruritis.

Other less frequently observed adverse reactions expected from opioid analgesics, including Benadryl CD (Codeine Phosphate) Sulfate Tablets, include:

Cardiovascular System: faintness, flushing, hypotension, palpitations, syncope

Digestive System: abdominal cramps, anorexia, diarrhea, dry mouth, gastrointestinal distress, pancreatitis

Nervous System: anxiety, drowsiness, fatigue, headache, insomnia, nervousness, shakiness, somnolence, vertigo, visual disturbances, weakness

Skin and Appendages: rash, sweating, urticaria

Serotonin Syndrome: Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs.

Adrenal Insufficiency: Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use.

Anaphylaxis:Anaphylaxis has been reported with ingredients contained in Benadryl CD (Codeine Phosphate) Sulfate Tablets.

Androgen Deficiency: Cases of androgen deficiency have occurred with chronic use of opioids .

The most common adverse reactions include: drowsiness, lightheadedness, dizziness, sedation, shortness of breath, nausea, vomiting, and sweating. (6)

To report SUSPECTED ADVERSE REACTIONS, contact West-Ward Pharmaceuticals Corp. at 1-800-962-8364 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

7 DRUG INTERACTIONS

Table 1 includes clinically significant drug interactions with Benadryl CD (Codeine Phosphate) Sulfate Tablets.

• Serotonergic Drugs: Concomitant use may result in serotonin syndrome. Discontinue Benadryl CD (Codeine Phosphate) sulfate if serotonin syndrome is suspected. (7)
• Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics: Avoid use with Benadryl CD (Codeine Phosphate) Sulfate Tablets because they may reduce analgesic effect of Benadryl CD (Codeine Phosphate) Sulfate Tablets or precipitate withdrawal symptoms. (7)

8 USE IN SPECIFIC POPULATIONS

• Pregnancy: May cause fetal harm.
• Lactation: Breastfeeding not recommended. (8.2)

8.1 Pregnancy

Pregnancy Category C

Risk Summary

Prolonged use of opioid analgesics during pregnancy may cause neonatal opioid withdrawal syndrome . Available data with Benadryl CD (Codeine Phosphate) Sulfate Tablets are insufficient to inform a drug-associated risk for major birth defects and miscarriage. In animal reproduction studies, Benadryl CD (Codeine Phosphate) administration during organogenesis has been shown to produce delayed ossification in the offspring of mice at 1.4 times maximum recommended human dose (MRHD) of 360 mg/day, embryolethal and fetotoxic effects in the offspring of rats and hamsters at approximately 2 to 3 times the MRHD, and cranial malformations/cranioschisis in the offspring of hamsters between 2 and 8 times the MRHD [see Data ].

All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively.

Clinical Considerations

Fetal/Neonatal Adverse Reactions: Prolonged use of opioid analgesics during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth.

Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly .

Labor or Delivery: Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. Benadryl CD (Codeine Phosphate) Sulfate Tablets are not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including Benadryl CD (Codeine Phosphate) Sulfate Tablets, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression.

Data

Animal Data: Studies on the reproductive and developmental effects of Benadryl CD (Codeine Phosphate) have been reported in the published literature in hamsters, rats, mice and rabbits.

In a study in which pregnant hamsters were administered 150 mg/kg twice daily of Benadryl CD (Codeine Phosphate) (oral; approximately 7 times the maximum recommended daily dose of 360 mg/day for adults on a mg/m² basis) during organogenesis cranial malformations (i.e., meningoencephalocele) in several fetuses were reported; as well as the observation of increases in the percentage of resorptions per litter. Doses of 50 and 150 mg/kg, bid resulted in fetotoxicity as demonstrated by decreased fetal body weight. In an earlier study in hamsters, single oral doses of 73 to 360 mg/kg level on Gestation Day 8 (oral; approximately 2 to 8 times the maximum recommended daily dose of 360 mg/day for adults on a mg/m² basis), reportedly produced cranioschisis in all of the fetuses examined.

In studies in rats, doses at the 120 mg/kg level (oral; approximately 3 times the maximum recommended daily dose of 360 mg/day for adults on a mg/m² basis) during organogenesis, in the toxic range for the adult animal, were associated with an increase in embryo resorption at the time of implantation.

In pregnant mice, a single 100 mg/kg dose (subcutaneous; approximately 1.4 times the recommended daily dose of 360 mg/day for adults on a mg/mg² basis) administered between Gestation Day 7 and 12 reportedly resulted in delayed ossification in the offspring.

No teratogenic effects were observed in rabbits administered up to 30 mg/kg (approximately 2 times the maximum recommended daily dose of 360 mg/day for adults on a mg/m² basis) of Benadryl CD (Codeine Phosphate) during organogenesis.

Benadryl CD (Codeine Phosphate) (30 mg/kg) administered subcutaneously to pregnant rats during pregnancy and for 25 days after delivery increased neonatal mortality at birth. This dose is 0.8 times the maximum recommended human dose of 360 mg/day on a body surface area comparison.

8.2 Lactation

Risk Summary

Benadryl CD and its active metabolite, morphine, are present in human milk. There are published studies and cases that have reported excessive sedation, respiratory depression, and death in infants exposed to Benadryl CD (Codeine Phosphate) via breast milk. Women who are ultra-rapid metabolizers of Benadryl CD (Codeine Phosphate) achieve higher than expected serum levels of morphine, potentially leading to higher levels of morphine in breast milk that can be dangerous in their breastfed infants. In women with normal Benadryl CD (Codeine Phosphate) metabolism (normal CYP2D6 activity), the amount of Benadryl CD (Codeine Phosphate) secreted into human milk is low and dose-dependent.

There is no information on the effects of Benadryl CD (Codeine Phosphate) on milk production. Because of the potential for serious adverse reactions, including excess sedation, respiratory depression, and death in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with Benadryl CD (Codeine Phosphate) Sulfate Tablets [see Warnings and Precautions (5.3)].

Clinical Considerations

If infants are exposed to Benadryl CD (Codeine Phosphate) Sulfate Tablets through breast milk, they should be monitored for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breastfeeding is stopped.

8.3 Females and Males of Reproductive Potential

Infertility

Chronic use of opioids may cause reduced fertility in females and males of reproductive potential. It is not known whether these effects on fertility are reversible .

8.4 Pediatric Use

The safety and effectiveness of Benadryl CD Sulfate Tablets in pediatric patients have not been established.

Life-threatening respiratory depression and death have occurred in children who received Benadryl CD (Codeine Phosphate) . In most of the reported cases, these events followed tonsillectomy and/or adenoidectomy, and many of the children had evidence of being ultra-rapid metabolizers of Benadryl CD (Codeine Phosphate) (i.e., multiple copies of the gene for cytochrome P450 isoenzyme 2D6 or high morphine concentrations). Children with sleep apnea may be particularly sensitive to the respiratory depressant effects of Benadryl CD (Codeine Phosphate). Because of the risk of life-threatening respiratory depression and death:

• Benadryl CD (Codeine Phosphate) Sulfate Tablets are contraindicated for all children younger than 12 years of age .
• Benadryl CD (Codeine Phosphate) Sulfate Tablets are contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy .
• Avoid the use of Benadryl CD (Codeine Phosphate) Sulfate Tablets in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of Benadryl CD (Codeine Phosphate) unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression .

8.5 Geriatric Use

Elderly patients (aged 65 years or older) may have increased sensitivity to Benadryl CD (Codeine Phosphate). In general, use caution when selecting a dosage for an elderly patient, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy.

Respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. Titrate the dosage of Benadryl CD (Codeine Phosphate) Sulfate Tablets slowly in geriatric patients and monitor closely for signs of central nervous system and respiratory depression .

Benadryl CD (Codeine Phosphate) 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 Hepatic Impairment

No formal studies have been conducted in patients with hepatic impairment so the pharmacokinetics of Benadryl CD in this patient population are unknown. Start these patients with a lower than normal dosage of Benadryl CD (Codeine Phosphate) Sulfate Tablets or with longer dosing intervals and titrate slowly while monitoring for signs of respiratory depression, sedation, and hypotension.

8.7 Renal Impairment

Benadryl CD (Codeine Phosphate) pharmacokinetics may be altered in patients with renal failure. Clearance may be decreased and the metabolites may accumulate to much higher plasma levels in patients with renal failure as compared to patients with normal renal function. Start these patients with a lower than normal dosage of Benadryl CD (Codeine Phosphate) Sulfate Tablets or with longer dosing intervals and titrate slowly while monitoring for signs of respiratory depression, sedation, and hypotension.

9 DRUG ABUSE AND DEPENDENCE

9.1 Controlled Substance

Benadryl CD Sulfate Tablets contain Benadryl CD (Codeine Phosphate), a Schedule II controlled substance.

9.2 Abuse

Benadryl CD (Codeine Phosphate) Sulfate Tablets contains Benadryl CD (Codeine Phosphate), a substance with a high potential for abuse similar to other opioids including fentanyl, hydrocodone, hydromorphone, methadone, morphine, oxycodone, oxymorphone, and tapentadol. Benadryl CD (Codeine Phosphate) Sulfate Tablets can be abused and is subject to misuse, addiction, and criminal diversion .

All patients treated with opioids require careful monitoring for signs of abuse and addiction, because use of opioid analgesic products carry the risk of addiction even under appropriate medical use.

Prescription drug abuse is the intentional non-therapeutic use of a prescription drug, even once, for its rewarding psychological or physiological effects.

Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that develop after repeated substance use and includes: a strong desire to take the drug, difficulties in controlling its use, persisting in its use despite harmful consequences, a higher priority given to drug use than to other activities and obligations, increased tolerance, and sometimes a physical withdrawal.

“Drug-seeking” behavior is very common in persons with substance use disorders. Drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated “loss” of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating healthcare provider(s). “Doctor shopping” (visiting multiple prescribers to obtain additional prescriptions) is common among drug abusers and people suffering from untreated addiction. Preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with poor pain control.

Abuse and addiction are separate and distinct from physical dependence and tolerance. Healthcare providers should be aware that addiction may not be accompanied by concurrent tolerance and symptoms of physical dependence in all addicts. In addition, abuse of opioids can occur in the absence of true addiction.

Benadryl CD (Codeine Phosphate) Sulfate Tablets, like other opioids, can be diverted for non-medical use into illicit channels of distribution. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised.

Proper assessment of the patient, proper prescribing practices, periodic re-evaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs.

Risks Specific to Abuse of Benadryl CD (Codeine Phosphate) Sulfate Tablets

Benadryl CD (Codeine Phosphate) Sulfate Tablets are for oral use only. Abuse of Benadryl CD (Codeine Phosphate) Sulfate Tablets poses a risk of overdose and death. The risk is increased with concurrent use of Benadryl CD (Codeine Phosphate) Sulfate Tablets with alcohol and other central nervous system depressants. Parenteral drug abuse is commonly associated with transmission of infection diseases such as hepatitis and HIV.

9.3 Dependence

Both tolerance and physical dependence can develop during chronic opioid therapy. Tolerance is the need for increasing doses of opioids to maintain a defined effect such as analgesia (in the absence of disease progression or other external factors). Tolerance may occur to both the desired and undesired effects of drugs, and may develop at different rates for different effects.

Physical dependence results in withdrawal symptoms after abrupt discontinuation or a significant dosage reduction of a drug. Withdrawal also may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone, nalmefene), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). Physical dependence may not occur to a clinically significant degree until after several days to weeks of continued opioid usage.

Benadryl CD (Codeine Phosphate) Sulfate Tablets should not be abruptly discontinued in a physically-dependent patient . If Benadryl CD (Codeine Phosphate) Sulfate Tablets are abruptly discontinued in a physically-dependent patient, a withdrawal syndrome may occur. Some or all of the following can characterize this syndrome: restlessness, lacrimation, rhinorrhea, yawning, perspiration, chills, myalgia, and mydriasis. Other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate.

Infants born to mothers physically dependent on opioids will also be physically dependent and may exhibit respiratory difficulties and withdrawal signs .

10 OVERDOSAGE

Clinical Presentation

Acute overdose with Benadryl CD (Codeine Phosphate) Sulfate Tablets can be manifested by respiratory depression, somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, and, in some cases, pulmonary edema, bradycardia, hypotension, partial or complete airway obstruction, atypical snoring, and death. Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations .

Treatment of Overdose

In case of overdose, priorities are the reestablishment of a patent and protected airway and institution of assisted or controlled ventilation, if needed. Employ other supportive measures (including oxygen and vasopressors) in the management of circulatory shock and pulmonary edema as indicated. Cardiac arrest or arrhythmias will require advanced life-support techniques.

The opioid antagonists, naloxone or nalmefene, are specific antidotes to respiratory depression resulting from opioid overdose. For clinically significant respiratory or circulatory depression secondary to Benadryl CD (Codeine Phosphate) overdose, administer an opioid antagonist. Opioid antagonists should not be administered in the absence of clinically significant respiratory or circulatory depression secondary to Benadryl CD (Codeine Phosphate) overdose.

Because the duration of opioid reversal is expected to be less than the duration of action of Benadryl CD (Codeine Phosphate) in Benadryl CD (Codeine Phosphate) Sulfate Tablets, carefully monitor the patient until spontaneous respiration is reliably reestablished. If the response to an opioid antagonist is suboptimal or only brief in nature, administer additional antagonist as directed by the product’s prescribing information.

In an individual physically dependent on opioids, administration of the recommended usual dosage of the antagonist will precipitate an acute withdrawal syndrome. The severity of the withdrawal symptoms experienced will depend on the degree of physical dependence and the dose of the antagonist administered. If a decision is made to treat serious respiratory depression in the physically dependent patient, administration of the antagonist should be begun with care and by titration with smaller than usual doses of the antagonist.

11 DESCRIPTION

Benadryl CD (Codeine Phosphate) Sulfate Tablets USP contain Benadryl CD (Codeine Phosphate), an opioid agonist, available for oral administration containing either 15 mg, 30 mg, or 60 mg of Benadryl CD (Codeine Phosphate) sulfate USP. The chemical name is morphinan-6-ol,7,8-didehydro-4,5-epoxy-3-methoxy-17-methyl-(5α,6α)-, sulfate (2:1) (salt), trihydrate. Its molecular formula is (C₁₈H₂₁NO₃)₂ - H₂SO₄ - 3H₂O and its molecular weight is 750.85 g/mol.

Its structure is as follows:

Benadryl CD (Codeine Phosphate) sulfate trihydrate is a fine, white, crystalline powder which is soluble in water and insoluble in chloroform and ether.

The inactive ingredients in Benadryl CD (Codeine Phosphate) Sulfate Tablets USP include: colloidal silicon dioxide, microcrystalline cellulose, pregelatinized starch and stearic acid.

chem.jpg

12 CLINICAL PHARMACOLOGY

12.1 Mechanism of Action

Benadryl CD sulfate is an opioid agonist relatively selective for the mu-opioid receptor, but with a much weaker affinity than morphine. The analgesic properties of Benadryl CD (Codeine Phosphate) have been speculated to come from its conversion to morphine, although the exact mechanism of analgesic action remains unknown.

12.2 Pharmacodynamics

Effects on the Central Nervous System

Benadryl CD (Codeine Phosphate) produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation.

Benadryl CD (Codeine Phosphate) causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations.

Effects on the Gastrointestinal Tract and Other Smooth Muscle

Benadryl CD (Codeine Phosphate) causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm, resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase.

Effects on the Cardiovascular System

Benadryl CD (Codeine Phosphate) produces peripheral vasodilation which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes, sweating, and/or orthostatic hypotension.

Effects on the Endocrine System

Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormone (LH) in humans . They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon. Chronic use of opioids may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date .

Effects on the Immune System

Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive.

Concentration–Efficacy Relationships

The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with potent agonist opioids. The minimum effective analgesic concentration of Benadryl CD (Codeine Phosphate) for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome, and/or the development of analgesic tolerance .

Concentration–Adverse Reaction Relationships

There is a relationship between increasing Benadryl CD (Codeine Phosphate) plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions .

12.3 Pharmacokinetics

Absorption

Benadryl CD (Codeine Phosphate) is absorbed from the gastrointestinal tract with maximum plasma concentration occurring 60 minutes post administration. Administration of 15 mg of Benadryl CD (Codeine Phosphate) sulfate every four hours for 5 days resulted in steady-state concentrations of Benadryl CD (Codeine Phosphate), morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) within 48 hours.

Food Effect: When 60 mg Benadryl CD (Codeine Phosphate) sulfate was administered 30 minutes after ingesting a high fat/high calorie meal, there was no significant change in the rate and extent of absorption of Benadryl CD (Codeine Phosphate).

Distribution

Benadryl CD (Codeine Phosphate) has been reported to have an apparent volume of distribution of approximately 3 to 6 L/kg, indicating extensive distribution of the drug into tissues. Benadryl CD (Codeine Phosphate) has low plasma protein binding with about 7% to 25% of Benadryl CD (Codeine Phosphate) bound to plasma proteins.

Elimination

Benadryl CD (Codeine Phosphate) is metabolized by conjugation to codeine-6-glucuronide (70% to 80%), by O-demethylation to morphine (5% to 10%), and by N-demethylation to norcodeine (~10%). Approximately 90% of the total dose of Benadryl CD (Codeine Phosphate) is excreted through the kidneys. The plasma half-lives of Benadryl CD (Codeine Phosphate) and its metabolites have been reported to be approximately 3 hours.

Metabolism: About 70% to 80% of the administered dose of Benadryl CD (Codeine Phosphate) is metabolized by conjugation with glucuronic acid to codeine-6-glucuronide (C6G) and via O-demethylation to morphine (about 5% to 10%) and N-demethylation to norcodeine (about 10%) respectively. UDP-glucuronosyltransferase (UGT) 2B7 and 2B4 are the major enzymes mediating glucurodination of Benadryl CD (Codeine Phosphate) to C6G. Cytochrome P450 2D6 is the major enzyme responsible for conversion of Benadryl CD (Codeine Phosphate) to morphine and P450 3A4 is the major enzyme mediating conversion of Benadryl CD (Codeine Phosphate) to norcodeine. Morphine and norcodeine are further metabolized by conjugation with glucuronic acid. The glucuronide metabolites of morphine are morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G). Morphine and M6G are known to have analgesic activity in humans. The analgesic activity of C6G in humans is unknown. Norcodeine and M3G are generally not considered to possess analgesic properties.

Excretion: Approximately 90% of the total dose of Benadryl CD (Codeine Phosphate) is excreted through the kidneys, of which approximately 10% is unchanged Benadryl CD (Codeine Phosphate). Plasma half-lives of Benadryl CD (Codeine Phosphate) and its metabolites have been reported to be approximately 3 hours.

13 NONCLINICAL TOXICOLOGY

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

Two-year carcinogenicity studies have been conducted in F344/N rats and B6C3F1 mice. There was no evidence of carcinogenicity in male and female rats, respectively, at dietary doses up to 70 and 80 mg/kg/day of Benadryl CD (Codeine Phosphate) (approximately 2 times the maximum recommended daily dose of 360 mg/day for adults on a mg/m² basis) for two years. Similarly there was no evidence of carcinogenicity activity in male and female mice at dietary doses up to 400 mg/kg/day of Benadryl CD (Codeine Phosphate) (approximately 5 times the maximum recommended daily dose of 360 mg/day for adults on a mg/m² basis) for two years.

Mutagenesis

Benadryl CD (Codeine Phosphate) was not mutagenic in the in vitro bacterial reverse mutation assay or clastogenic in the in vitro Chinese hamster ovary cell chromosome aberration assay.

Impairment of Fertility

No animal studies were conducted to evaluate the effect of Benadryl CD (Codeine Phosphate) on male or female fertility.

16 HOW SUPPLIED/STORAGE AND HANDLING

Benadryl CD (Codeine Phosphate) Sulfate Tablets USP

15 mg tablet: supplied as white to off-white biconvex tablets with “15” debossed on the scored side and “54 613” debossed on the other side.

NDC 0054-0243-24: 100 (4 blister packs per carton x 25 tablets per blister pack) Unit-Dose Tablets

30 mg tablet: supplied as white to off-white biconvex tablets with “30” debossed on the scored side and “54 783” debossed on the other side.

NDC 0054-0244-24: 100 (4 blister packs per carton x 25 tablets per blister pack) Unit-Dose Tablets

NDC 0054-0244-25: Bottle of 100 Tablets

60 mg tablet: supplied as white to off-white biconvex tablets with “60” debossed on the scored side and “54 412” debossed on the other side.

NDC 0054-0245-25: Bottle of 100 Tablets

Storage

Store at 20° to 25°C (68° to 77°F), excursions permitted between 15° to 30°C (59° to 86°F).

Protect from moisture.

Dispense in a tight, light-resistant container as defined in the USP/NF.

Blisters are not child-resistant. Use child-resistant closure if dispensing to outpatient.

17 PATIENT COUNSELING INFORMATION

Advise the patient to read the FDA-approved patient labeling (Medication Guide).

Addiction, Abuse, and Misuse

Inform patients that the use of Benadryl CD (Codeine Phosphate) Sulfate Tablets, even when taken as recommended, can result in addiction, abuse, and misuse, which can lead to overdose and death . Instruct patients not to share Benadryl CD (Codeine Phosphate) Sulfate Tablets with others and to take steps to protect Benadryl CD (Codeine Phosphate) Sulfate Tablets from theft or misuse.

Life-Threatening Respiratory Depression

Inform patients of the risk of life-threatening respiratory depression, including information that the risk is greatest when starting Benadryl CD (Codeine Phosphate) Sulfate Tablets or when the dosage is increased, and that it can occur even at recommended dosages . Advise patients how to recognize respiratory depression and to seek medical attention if breathing difficulties develop.

Accidental Ingestion

Inform patients that accidental ingestion, especially by children, may result in respiratory depression or death .

Instruct patients to take steps to store Benadryl CD (Codeine Phosphate) sulfate securely and to properly dispose of unused Benadryl CD (Codeine Phosphate) Sulfate Tablets in accordance with the local state guidelines and/or regulations.

Ultra-Rapid Benadryl CD (Codeine Phosphate) Metabolism of Benadryl CD (Codeine Phosphate) and Other Risk Factors for Life-Threatening Respiratory Depression in Children

Advise caregivers that Benadryl CD (Codeine Phosphate) Sulfate Tablets are contraindicated in all children younger than 12 years of age and in children younger than 18 years of age following tonsillectomy and/or adenoidectomy. Advise caregivers of children 12 to 18 years of age receiving Benadryl CD (Codeine Phosphate) Sulfate Tablets to monitor for signs of respiratory depression .

Interactions with Benzodiazepines and Other CNS Depressants

Inform patients and caregivers that potentially fatal additive effects may occur if Benadryl CD (Codeine Phosphate) Sulfate Tablets are used with benzodiazepines or other CNS depressants, including alcohol, and not to use these concomitantly unless supervised by a healthcare provider .

Serotonin Syndrome

Inform patients that opioids could cause a rare but potentially life-threatening condition resulting from concomitant administration of serotonergic drugs. Warn patients of the symptoms of serotonin syndrome and to seek medical attention right away if symptoms develop. Instruct patients to inform their physicians if they are taking, or plan to take serotonergic medications .

MAOI Interaction

Inform patients not to take Benadryl CD (Codeine Phosphate) Sulfate Tablets while using any drugs that inhibit monoamine oxidase. Patients should not start MAOIs while taking Benadryl CD (Codeine Phosphate) Sulfate Tablets .

Adrenal Insufficiency

Inform patients that opioids could cause adrenal insufficiency, a potentially life-threatening condition. Adrenal insufficiency may present with non-specific symptoms and signs such as nausea, vomiting, anorexia, fatigue, weakness, dizziness, and low blood pressure. Advise patients to seek medical attention if they experience a constellation of these symptoms .

Important Administration Instructions

Instruct patients how to properly take Benadryl CD (Codeine Phosphate) Sulfate Tablets.

• Advise patients not to adjust the dose of Benadryl CD (Codeine Phosphate) Sulfate Tablets without consulting a physician or other healthcare professional.
• If patients have been receiving treatment with Benadryl CD (Codeine Phosphate) Sulfate Tablets for more than a few weeks and cessation of therapy is indicated, counsel them on the importance of safely tapering the dose and that abruptly discontinuing the medication could precipitate withdrawal symptoms. Provide a dose schedule to accomplish a gradual discontinuation of the medication .

Hypotension

Inform patients that Benadryl CD (Codeine Phosphate) Sulfate Tablets may cause orthostatic hypotension and syncope. Instruct patients how to recognize symptoms of low blood pressure and how to reduce the risk of serious consequences should hypotension occur (e.g., sit or lie down, carefully rise from a sitting or lying position) .

Anaphylaxis

Inform patients that anaphylaxis has been reported with ingredients contained in Benadryl CD (Codeine Phosphate) Sulfate Tablets. Advise patients how to recognize such a reaction and when to seek medical attention .

Pregnancy

Neonatal Opioid Withdrawal Syndrome: Inform female patients of reproductive potential that prolonged use of Benadryl CD (Codeine Phosphate) Sulfate Tablets during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and treated .

Embryo-Fetal Toxicity: Inform female patients of reproductive potential that Benadryl CD (Codeine Phosphate) Sulfate Tablets can cause fetal harm and to inform the healthcare provider of a known or suspected pregnancy .

Lactation

Advise women that breastfeeding is not recommended during treatment with Benadryl CD (Codeine Phosphate) Sulfate Tablets [see Use in Specific Populations (8.2)].

Infertility

Inform patients that chronic use of opioids may cause reduced fertility. It is not known whether these effects on fertility are reversible [see Use in Specific Populations (8.3)].

Driving or Operating Heavy Machinery

Inform patients that Benadryl CD (Codeine Phosphate) Sulfate Tablets may impair the ability to perform potentially hazardous activities such as driving a car or operating heavy machinery. Advise patients not to perform such tasks until they know how they will react to the medication .

Constipation

Advise patients of the potential for severe constipation, including management instructions and when to seek medical attention .

Disposal of Unused Benadryl CD (Codeine Phosphate) Sulfate Tablets

Advise patients to properly dispose of unused Benadryl CD (Codeine Phosphate) Sulfate Tablets. Advise patients to throw the drug in the household trash following these steps. 1) Remove them from their original containers and mix them with an undesirable substance, such as used coffee grounds or kitty litter (this makes the drug less appealing to children and pets, and unrecognizable to people who may intentionally go through the trash seeking drugs). 2) Place the mixture in a sealable bag, empty can, or other container to prevent the drug from leaking or breaking out of a garbage bag, or to dispose of in accordance with local state guidelines and/or regulations.

• Distr. by West-Ward
• Pharmaceuticals Corp.
• Eatontown, NJ 07724
• 10005657/10
• Revised August 2017

Medication Guide

10005657/10

Revised August 2017

carton-15mg-tab-07.jpg

Diphenhydramine Hydrochloride:

• Pharmacological action
• Pharmacokinetics
• Why is Benadryl CD Xepa-Soul Pattinson prescribed?
• Dosage and administration
• Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson side effects, adverse reactions
• Benadryl CD Xepa-Soul Pattinson contraindications
• Using during pregnancy and breastfeeding
• Special instructions
• Precautionary measures
• Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson drug interactions
• Benadryl CD Xepa-Soul Pattinson in case of emergency / overdose
• Benadryl CD (Diphenhydramine Hydrochloride) reviews

Pharmacological action

Benadryl CD Xepa-Soul Pattinson is a blocker of histamine H1-receptors. It has antiallergic activity, has a local anesthetic, antispasmodic and mild ganglion blocking action.

When Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson administered orally Benadryl CD (Diphenhydramine Hydrochloride) has a sedative and hypnotic effects, has a moderate antiemetic effect and has a central holinoliticheskoy activity.

When applied externally it has antiallergic effect.

Pharmacokinetics

Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson is rapidly absorbed from the gastrointestinal tract. Bioavailability is 50%. C_max is achieved after 20-40 min (in the greatest concentration is determined in the lungs, spleen, kidneys, liver, brain and muscles). Binding to plasma proteins - 98-99%. Penetrates through the BBB. Metabolised mainly in the liver, partly - in the lungs and kidneys. T1/2 is 4-10 hours. Within one day completely removed kidneys as metabolites conjugated to glucuronic acid. Significant quantities are derived from milk and can cause sedation in infants (may be a paradoxical reaction characterized by hyperexcitability).

Why is Benadryl CD Xepa-Soul Pattinson prescribed?

Allergic reactions (urticaria, hay fever, angioedema), allergic conjunctivitis, vasomotor rhinitis, Henoch-Schonlein purpura, serum sickness, itchy dermatitis, sleep disorders (monotherapy or in combination with drugs), chorea, sea and air sickness, vomiting in pregnancy, Meniere's syndrome, premedication.

Dosage and administration

Oral, IV, IM, rectal, topical, intranasal, in the conjunctival sac. Oral dose of Benadryl CD Xepa-Soul Pattinson for adults is 30-50 mg 1-3 times / day. The treatment course is 10-15 days. As soporific - 50 mg at bedtime. IM in doses of 50-250 mg; IV in drip - 20-50 mg. When oral administered single dose for children under 1 year - 2-5 mg; from 2 to 5 years - 5-15 mg; of 6 to 12 years - 15-30 mg. Externally applied 1-2 times / day.

Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson side effects, adverse reactions

Possible: a short-term numbness in the oral mucosa, drowsiness, weakness, decrease in psychomotor speed of reaction in children may be a paradoxical development of insomnia, irritability, and euphoria.

Rarely: dizziness, headache, dry mouth, nausea, photosensitivity, paresis of accommodation, poor coordination of movements, tremor.

Benadryl CD Xepa-Soul Pattinson contraindications

Closure glaucoma, prostatic hypertrophy, stenosing peptic ulcer, stenosis of the bladder neck, bronchial asthma, epilepsy, hypersensitivity to Benadryl CD (Diphenhydramine Hydrochloride).

Using during pregnancy and breastfeeding

During pregnancy and lactation, Benadryl CD (Diphenhydramine Hydrochloride) used with caution, according to strict indications, when the expected therapeutic effect for the mother outweighs the potential risk to the fetus or infant.

Special instructions

With careful use Benadryl CD (Diphenhydramine Hydrochloride) during pregnancy and lactation.

During the period of treatment with Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson should not be exposed to solar radiation should be avoided alcohol.

Used with caution in patients involved in potentially dangerous activities requiring attention and rapid psychomotor reactions.

Precautionary measures

Benadryl CD Xepa-Soul Pattinson is not recommended for SC injection. Since Benadryl CD (Diphenhydramine Hydrochloride) has atropinopodobnym action should be cautious in its use: patients with recent respiratory infection in history (including asthma), increased intraocular pressure in hyperthyroidism, cardiovascular system, hypotension. Antihistamines drugs can reduce mental alertness as well as in adults and children and also cause agitation and hallucinations, convulsions and death in infants and children, especially in overdose. Precautions apply at age 60 and older because more likely to develop dizziness, sedation and hypotension. During treatment with Benadryl CD (Diphenhydramine Hydrochloride) should avoid sun exposure. Should not be used during the drivers of vehicles and people, trade is connected with increased concentration. In the period of treatment should avoid drinking alcoholic beverages.

Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson drug interactions

When Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson applied simultaneously increases the effects of ethanol and drugs that depress the central nervous system.

With simultaneous use of Benadryl CD (Diphenhydramine Hydrochloride) Xepa-Soul Pattinson and MAO inhibitors increase the anticholinergic activity of Benadryl CD (Diphenhydramine Hydrochloride).

The antagonistic interaction observed with a joint appointment with psychostimulants.

Reduces the effectiveness of apomorphine as an emetic in the treatment of poisoning. Intensifies anticholinergic effects of drugs with anticholinergic activity.

Benadryl CD Xepa-Soul Pattinson in case of emergency / overdose

Symptoms: dry mouth, difficulty breathing, persistent mydriasis, flushing, depression or excitement (more common in children), CNS confusion; children - the development of convulsions and death.

Treatment: induction of vomiting, gastric lavage, the prescription of activated charcoal, symptomatic and supportive therapy on a background of careful monitoring of respiration and blood pressure levels.

Menthol:

• Benadryl CD (Menthol) reviews

Indication: Used to treat occasional minor irritation, pain, sore mouth, and sore throat as well as cough associated with a cold or inhaled irritants.

Benadryl CD (Menthol) is a covalent organic compound made synthetically or obtained from peppermint or other mint oils. Menthol's ability to chemically trigger cold-sensitive receptors in the skin is responsible for the well known cooling sensation that it provokes when inhalated, eaten, or applied to the skin. It should be noted that Benadryl CD (Menthol) does not cause an actual drop in temperature.

Sodium Citrate:

• Indications and usage
• Dosage and administration
• Dosage forms and strengths
• Contraindications
• Warnings and precautions
• Adverse reactions
• Drug interactions
• Use in specific populations
• Overdosage
• Description
• Clinical pharmacology
• Nonclinical toxicology
• Clinical studies
• How supplied/storage and handling
• Patient counseling information
• Benadryl CD (Sodium Citrate) reviews

1 INDICATIONS AND USAGE

Benadryl CD nitrite is indicated for sequential use with Benadryl CD (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

Benadryl CD (Sodium Citrate) Nitrite Injection is indicated for sequential use with Benadryl CD (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 Benadryl CD (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 Benadryl CD 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, Benadryl CD (Sodium Citrate) Nitrite Injection and Benadryl CD (Sodium Citrate) Thiosulfate Injection should be administered without delay.

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 Benadryl CD (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 Benadryl CD (Sodium Citrate) thiosulfate, simultaneously with Benadryl CD (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 Benadryl CD (Sodium Citrate) thiosulfate, with Benadryl CD (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

Redosing: If signs of cyanide poisoning reappear, repeat treatment using one-half the original dose of both Benadryl CD (Sodium Citrate) nitrite and Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite, followed by Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite and Benadryl CD (Sodium Citrate) thiosulfate.

Benadryl CD (Sodium Citrate) nitrite injection and Benadryl CD (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. Benadryl CD (Sodium Citrate) nitrite should be administered first, followed immediately by Benadryl CD (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.

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

In adult and pediatric patients with known anemia, it is recommended that the dosage of Benadryl CD (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 Benadryl CD 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 Benadryl CD (Sodium Citrate) nitrite solely to achieve an arbitrary level of methemoglobinemia may be unnecessary and potentially hazardous. The therapeutic effects of Benadryl CD (Sodium Citrate) nitrite do not appear to be mediated by methemoglobin formation alone and clinical responses to Benadryl CD (Sodium Citrate) nitrite administration have been reported in association with methemoglobin levels of less than 10%. Administration of Benadryl CD (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 Benadryl CD (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 Benadryl CD (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 Benadryl CD (Sodium Citrate) thiosulfate and Benadryl CD (Sodium Citrate) nitrite, when administered sequentially through the same IV line as described in Dosage and Administration.

3 DOSAGE FORMS AND STRENGTHS

Benadryl CD (Sodium Citrate) Nitrite Injection consists of:

• One vial of Benadryl CD (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: Benadryl CD 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 Benadryl CD (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. Benadryl CD (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 Benadryl CD (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 Benadryl CD nitrite.

Methemoglobin levels should be monitored and oxygen administered during treatment with Benadryl CD (Sodium Citrate) nitrite whenever possible. When Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite administered to an adult. Benadryl CD (Sodium Citrate) nitrite should be used with caution in the presence of other drugs that may cause methemoglobinemia such as procaine and nitroprusside. Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite, and infusion rates should be slowed if hypotension occurs.

5.3 Anemia

Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite dose that is reduced in proportion to their oxygen carrying capacity.

5.4 Smoke Inhalation Injury

Benadryl CD 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 Benadryl CD (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 Benadryl CD 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 Benadryl CD (Sodium Citrate) nitrite.

5.7 Use with Other Drugs

Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite.

The medical literature has reported the following adverse events in association with Benadryl CD (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 Benadryl CD (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 Benadryl CD (Sodium Citrate) Nitrite Injection.

8 USE IN SPECIFIC POPULATIONS

• Renal impairment: Benadryl CD 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. Benadryl CD (Sodium Citrate) Nitrite Injection should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Benadryl CD (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 Benadryl CD (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 Benadryl CD (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, Benadryl CD (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, Benadryl CD (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 Benadryl CD (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 Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite that would be used to treat cyanide poisoning, based on a body surface area comparison).

Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite that were detectable postnatally. Specifically, animals that were exposed prenatally to Benadryl CD (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, Benadryl CD 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 Benadryl CD (Sodium Citrate) nitrite is excreted in human milk. Because Benadryl CD (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 Benadryl CD (Sodium Citrate) Nitrite Injection administration to a nursing woman. There are no data to determine when breastfeeding may be safely restarted following administration of Benadryl CD (Sodium Citrate) nitrite. In studies conducted with Long-Evans rats, Benadryl CD (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 Benadryl CD nitrite in conjunction with Benadryl CD (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 Benadryl CD (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.

Benadryl CD (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 Benadryl CD (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

Benadryl CD (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

Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite result in severe hypotension and toxic levels of methemoglobin which may lead to cardiovascular collapse.

Benadryl CD (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 Benadryl CD (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 Benadryl CD (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

Benadryl CD (Sodium Citrate) nitrite has the chemical name nitrous acid Benadryl CD (Sodium Citrate) salt. The chemical formula is NaNO₂ and the molecular weight is 69.0. The structural formula is:

Structure of Benadryl CD (Sodium Citrate) Nitrite

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

Benadryl CD (Sodium Citrate) nitrite injection is a sterile aqueous solution and is intended for intravenous injection. Each vial contains 300 mg of Benadryl CD (Sodium Citrate) nitrite in 10 mL solution (30 mg/mL). Benadryl CD (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 Benadryl CD nitrite and Benadryl CD (Sodium Citrate) thiosulfate is the result of differences in their primary mechanisms of action as antidotes for cyanide poisoning.

Benadryl CD (Sodium Citrate) Nitrite

Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite. It has been suggested that Benadryl CD (Sodium Citrate) nitrite-induced methemoglobinemia may be more efficacious against cyanide poisoning than comparable levels of methemoglobinemia induced by other oxidants. Also, Benadryl CD (Sodium Citrate) nitrite appears to retain some efficacy even when the formation of methemoglobin is inhibited by methylene blue.

Benadryl CD (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. Benadryl CD (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

Benadryl CD (Sodium Citrate) Nitrite

When 4 mg/kg Benadryl CD (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 Benadryl CD (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 Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite is estimated to be 55 minutes.

12.3 Pharmacokinetics

Benadryl CD (Sodium Citrate) Nitrite

Benadryl CD (Sodium Citrate) nitrite is a strong oxidant, and reacts rapidly with hemoglobin to form methemoglobin. The pharmacokinetics of free Benadryl CD (Sodium Citrate) nitrite in humans have not been well studied. It has been reported that approximately 40% of Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite and Benadryl CD (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 Benadryl CD nitrite as part of a cyanide antidote outweighs concerns raised by the equivocal findings in chronic rodent studies. Benadryl CD (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. Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite may react in vivo with secondary amines to form carcinogenic nitrosamines in the stomach. Concurrent exposure to Benadryl CD (Sodium Citrate) nitrite and secondary amines in feed or drinking water resulted in an increase in the incidence of tumors in rodents.

Mutagenesis

Benadryl CD (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. Benadryl CD (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. Benadryl CD (Sodium Citrate) nitrite was negative in the in vitro chromosomal aberrations assay using human peripheral blood lymphocytes. Acute administration of Benadryl CD (Sodium Citrate) nitrite to male rats or male mice did not produce an increased incidence of micronuclei in bone marrow. Likewise, Benadryl CD (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 Benadryl CD (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 Benadryl CD (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 Benadryl CD (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 Benadryl CD (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 Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite and Benadryl CD (Sodium Citrate) thiosulfate in 1932-1933. Treatment consisted of intravenously administered 22.5 mg/kg (half the lethal dose) Benadryl CD (Sodium Citrate) nitrite or 1 g/kg Benadryl CD (Sodium Citrate) thiosulfate alone or in sequence immediately after subcutaneous injection of Benadryl CD (Sodium Citrate) cyanide into dogs over a range of doses. Subsequent doses of 10 mg/kg Benadryl CD (Sodium Citrate) nitrite and/or 0.5 g/kg Benadryl CD (Sodium Citrate) thiosulfate were administered when clinical signs or symptoms of poisoning persisted or reappeared. Either therapy administered alone increased the dose of Benadryl CD (Sodium Citrate) cyanide required to cause death, and when administered together, Benadryl CD (Sodium Citrate) nitrite and Benadryl CD (Sodium Citrate) thiosulfate resulted in a synergistic effect in raising the lethal dose of Benadryl CD (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 Benadryl CD (Sodium Citrate) nitrite and Benadryl CD (Sodium Citrate) thiosulfate in the treatment of cyanide poisoning.

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

14 CLINICAL STUDIES

The human data supporting the use of Benadryl CD (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 Benadryl CD (Sodium Citrate) thiosulfate report its use in conjunction with Benadryl CD (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 Benadryl CD (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 Benadryl CD (Sodium Citrate) Nitrite carton (NDC 60267-311-10) consists of the following:

• One 10 mL glass vial of Benadryl CD (Sodium Citrate) nitrite injection 30 mg/mL (containing 300 mg of Benadryl CD (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: Benadryl CD (Sodium Citrate) Thiosulfate must be obtained separately.)

17 PATIENT COUNSELING INFORMATION

Benadryl CD 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

Benadryl CD (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

Benadryl CD (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