Merispas Tablets

Dicyclomine Hydrochloride:

• Description
• Clinical pharmacology
• Indications and usage
• Contraindications
• Warnings
• Precautions
• Adverse reactions
• Drug abuse and dependence
• Overdosage
• Dosage and administration
• How supplied
• Merispas Tablets (Dicyclomine Hydrochloride) reviews

DESCRIPTION

Merispas Tablets (Dicyclomine Hydrochloride) is an antispasmodic and anticholinergic (antimuscarinic) agent. Merispas Tablets (Dicyclomine Hydrochloride) occurs as a fine, white, crystalline, practically odorless powder with a bitter taste. It is soluble in water, freely soluble in alcohol and chloroform, and very slightly soluble in ether.

Chemically, it is [Bicyclohexyl]-1-carboxylic acid, 2-(diethyl-amino) ethyl ester, hydrochloride with the following structural formula:

C₁₉H₃₅NO₂-HCI   345.95

Each capsule, for oral administration, contains 10 mg of Merispas Tablets (Dicyclomine Hydrochloride).

Each tablet, for oral administration, contains 20 mg of Merispas Tablets (Dicyclomine Hydrochloride).

This product contains the following inactive ingredients: colloidal silicon dioxide (tablets only), corn starch (tablets only), D&C red #28 (capsules only), FD&C blue #1 (capsules only), FD&C blue #1 lake (tablets only), FD&C red #40 (capsules only), gelatin (capsules only), hypromellose (tablets only), lactose monohydrate (tablets only), magnesium stearate (capsules only), pregelatinized starch, silicon dioxide (capsules only), sodium lauryl sulfate (capsules only), sodium starch glycolate (tablets only), and stearic acid (tablets only).

Merispas Tablets (Dicyclomine Hydrochloride) Structural Formula

CLINICAL PHARMACOLOGY

Dicyclomine relieves smooth muscle spasm of the gastrointestinal tract. Animal studies indicate that this action is achieved via a dual mechanism: (1) a specific anticholinergic effect (antimuscarinic) at the acetylcholine- receptor sites with approximately 1/8 the milligram potency of atropine (in vitro, guinea pig ileum); and (2) a direct effect upon smooth muscle (musculotropic) as evidenced by dicyclomine's antagonism of bradykinin- and histamine-induced spasms of the isolated guinea pig ileum. Atropine did not affect responses to these two agonists. In vivo studies in cats and dogs showed dicyclomine to be equally potent against acetylcholine (ACh)- or barium chloride (BaCI₂)- induced intestinal spasm while atropine was at least 200 times more potent against effects of ACh than BaCI₂. Tests for mydriatic effects in mice showed that dicyclomine was approximately 1/500 as potent as atropine; antisialogogue tests in rabbits showed dicyclomine to be 1/300 as potent as atropine.

In man, dicyclomine is rapidly absorbed after oral administration, reaching peak values within 60-90 minutes. The principal route of elimination is via the urine (79.5% of the dose). Excretion also occurs in the feces, but to a lesser extent (8.4%). Mean half-life of plasma elimination in one study was determined to be approximately 1.8 hours when plasma concentrations were measured for 9 hours after a single dose. In subsequent studies, plasma concentrations were followed for up to 24 hours after a single dose, showing a secondary phase of elimination with a somewhat longer half-life. Mean volume of distribution for a 20 mg oral dose is approximately 3.65 L/kg suggesting extensive distribution in tissues.

In controlled clinical trials involving over 100 patients who received drug, 82% of patients treated for functional bowel/irritable bowel syndrome with Merispas Tablets (Dicyclomine Hydrochloride) at initial doses of 160 mg daily (40 mg q.i.d.) demonstrated a favorable clinical response compared with 55% treated with placebo (p<.05). In these trials, most of the side effects were typically anticholinergic in nature and were reported by 61% of the patients.

Nine percent (9%) of patients were discontinued from the drug because of one or more of these side effects (compared with 2% in the placebo group). In 41% of the patients with side effects, side effects disappeared or were tolerated at the 160 mg daily dose without reduction. A dose reduction from 160 mg daily to an average daily dose of 90 mg was required in 46% of the patients with side effects who then continued to experience a favorable clinical response; their side effects either disappeared or were tolerated.

INDICATIONS AND USAGE

For the treatment of functional bowel/irritable bowel syndrome.

CONTRAINDICATIONS

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  Obstructive uropathy
  

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  Obstructive disease of the gastrointestinal tract
  

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  Severe ulcerative colitis
  

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  Reflux esophagitis
  

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  Unstable cardiovascular status in acute hemorrhage
  

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  Glaucoma
  

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  Myasthenia gravis
  

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  Evidence of prior hypersensitivity to Merispas Tablets (Dicyclomine Hydrochloride) or other ingredients of these formulations
  

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  Infants less than 6 months of age
  

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  Nursing Mothers.
  

WARNINGS

In the presence of a high environmental temperature, heat prostration can occur with drug use (fever and heat stroke due to decreased sweating). If symptoms occur, the drug should be discontinued and supportive measures instituted.

Diarrhea may be an early symptom of incomplete intestinal obstruction, especially in patients with ileostomy or colostomy. In this instance, treatment with this drug would be inappropriate and possibly harmful.

Dicyclomine may produce drowsiness or blurred vision. The patient should be warned not to engage in activities requiring mental alertness, such as operating a motor vehicle or other machinery or performing hazardous work while taking this drug.

Psychosis has been reported in sensitive individuals given anticholinergic drugs. CNS signs and symptoms include confusion, disorientation, short-term memory loss, hallucinations, dysarthria, ataxia, coma, euphoria, decreased anxiety, fatigue, insomnia, agitation and mannerisms, and inappropriate affect. These CNS signs and symptoms usually resolve within 12 to 24 hours after discontinuation of the drug.

There are reports that administration of dicyclomine syrup to infants has been followed by serious respiratory symptoms (dyspnea, shortness of breath, breathlessness, respiratory collapse, apnea, asphyxia), seizures, syncope, pulse rate fluctuations, muscular hypotonia, and coma. Death has been reported. No causal relationship between these effects observed in infants and dicyclomine administration has been established. DICYCLOMINE IS CONTRAINDICATED IN INFANTS LESS THAN 6 MONTHS OF AGE AND IN NURSING MOTHERS..

Safety and efficacy of Merispas Tablets (Dicyclomine Hydrochloride) in pediatric patients have not been established.

PRECAUTIONS

General

Use with caution in patients with:

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  Autonomic neuropathy
  

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  Hepatic or renal disease
  

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  Ulcerative colitis-large doses may suppress intestinal motility to the point of producing a paralytic ileus and the use of this drug may precipitate or aggravate the serious complication of toxic megacolon
  

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  Hyperthyroidism
  

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  Hypertension
  

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  Coronary heart disease
  

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  Congestive heart failure
  

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  Cardiac tachyarrhythmia
  

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  Hiatal hernia
  

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  Known or suspected prostatic hypertrophy.
  

Investigate any tachycardia before administration of Merispas Tablets (Dicyclomine Hydrochloride), since it may increase the heart rate.

With overdosage, a curare-like action may occur (i.e., neuromuscular blockade leading to muscular weakness and possible paralysis).

Information For Patients

Dicyclomine may produce drowsiness or blurred vision. The patient should be warned not to engage in activities requiring mental alertness, such as operating a motor vehicle or other machinery or to perform hazardous work while taking this drug.

Dicyclomine is contraindicated in infants less than 6 months of age and in nursing mothers..

In the presence of a high environmental temperature, heat prostration can occur with drug use (fever and heat stroke due to decreased sweating).

If symptoms occur, the drug should be discontinued and a physician contacted.

Drug Interactions

The following agents may increase certain actions or side effects of anticholinergic drugs: amantadine, antiarrhythmic agents of Class I, antihistamines, antipsychotic agents (e.g., phenothiazines), benzodiazepines, MAO inhibitors, narcotic analgesics (e.g., meperidine), nitrates and nitrites, sympathomimetic agents, tricyclic antidepressants, and other drugs having anticholinergic activity.

Anticholinergics antagonize the effects of antiglaucoma agents. Anticholinergic drugs in the presence of increased intraocular pressure may be hazardous when taken concurrently with agents such as corticosteroids.

Anticholinergic agents may affect gastrointestinal absorption of various drugs, such as slowly dissolving dosage forms of digoxin; increased serum digoxin concentrations may result. Anticholinergic drugs may antagonize the effects of the drugs that alter gastrointestinal motility, such as metoclopramide. Because antacids may interfere with the absorption of anticholinergic agents, simultaneous use of these drugs should be avoided.

The inhibiting effects of anticholinergic drugs on gastric hydrochloric acid secretion are antagonized by agents used to treat achlorhydria and those used to test gastric secretion.

Carcinogenesis, Mutagenesis, Impairment of Fertility

There are no known human data on long-term potential for carcinogenicity or mutagenicity.

Long-term studies in animals to determine carcinogenic potential are not known to have been conducted.

In studies in rats at doses of up to 100 mg/kg/day, dicyclomine produced no deleterious effects on breeding, conception, or parturition.

Pregnancy

Teratogenic Effects

Pregnancy Category B.

Reproduction studies have been performed in rats and rabbits at doses up to 33 times the maximum recommended human dose based on 160 mg/day and have revealed no evidence of impaired fertility or harm to the fetus due to dicyclomine. Epidemiologic studies in pregnant women with products containing Merispas Tablets (Dicyclomine Hydrochloride) (at doses up to 40 mg/day) have not shown that dicyclomine increases the risk of fetal abnormalities if administered during the first trimester of pregnancy. There are, however, no adequate and well-controlled studies in pregnant women at the recommended doses (80-160 mg/day). Because animal reproduction studies are not always predictive of human response, dicyclomine as indicated for functional bowel/irritable bowel syndrome should be used during pregnancy only if clearly needed.

Nursing Mothers

Since dicyclomine has been reported to be excreted in human milk, Merispas Tablets (Dicyclomine Hydrochloride) IS CONTRAINDICATED IN NURSING MOTHERS..

Pediatric Use

DICYCLOMINE IS CONTRAINDICATED IN INFANTS LESS THAN 6 MONTHS OF AGE.

Safety and effectiveness in pediatric patients have not been established.

ADVERSE REACTIONS

Controlled clinical trials have provided frequency information for reported adverse effects of Merispas Tablets (Dicyclomine Hydrochloride) listed in a decreasing order of frequency.

Not all of the following adverse reactions have been reported with Merispas Tablets (Dicyclomine Hydrochloride). Adverse reactions are included here that have been reported for pharmacologically similar drugs with anticholinergic/antispasmodic action.

Gastrointestinal: dry mouth, nausea, vomiting, constipation, bloated feeling, abdominal pain, taste loss, anorexia

Central Nervous System: dizziness, light-headedness, tingling, headache, drowsiness, weakness, nervousness, numbness, mental confusion and/or excitement (especially in elderly persons), dyskinesia, lethargy, syncope, speech disturbance, insomnia

Ophthalmologic: blurred vision, diplopia, mydriasis, cycloplegia, increased ocular tension

Dermatological/Allergic: rash, urticaria, itching, and other dermal manifestations; severe allergic reaction or drug idiosyncrasies including anaphylaxis

Genitourinary: urinary hesitancy, urinary retention

Cardiovascular: tachycardia, palpitations

Respiratory: Dyspnea, apnea, asphyxia

Other: decreased sweating, nasal stuffiness or congestion, sneezing, throat congestion, impotence, suppression of lactation

DRUG ABUSE AND DEPENDENCE

Abuse of and/or dependence on dicyclomine for anticholinergic effects have been rarely reported.

OVERDOSAGE

Signs and Symptoms

The signs and symptoms of overdosage are headache; nausea; vomiting; blurred vision; dilated pupils; hot, dry skin; dizziness; dryness of the mouth; difficulty in swallowing; and CNS stimulation. A curare-like action may occur.

A 37-year-old female reported numbness on the left side, cold fingertips, blurred vision, abdominal and flank pain, decreased appetite, dry mouth, and nervousness following ingestion of 320 mg daily (four 20 mg tablets QID) for four days. These events resolved after discontinuing the dicyclomine.

Oral LD₅₀

The acute oral LD₅₀ of the drug is 625 mg/kg in mice.

Minimum Human Lethal Dose/Maximum Human Dose Recorded

The amount of drug in a single dose that is ordinarily associated with symptoms of overdosage or that is Iikely to be life threatening, has not been defined. The maximum human oral dose recorded was 600 mg by mouth in a 10-month-old child and approximately 1500 mg in an adult, each of whom survived.

In three of the infants who died following administration of Merispas Tablets (Dicyclomine Hydrochloride), the blood concentrations of drug were 200, 220, and 505 ng/mL, respectively.

Dialysis

It is not known if dicyclomine is dialyzable.

Treatment

Treatment should consist of gastric lavage, emetics, and activated charcoal. Sedatives (e.g., short-acting barbiturates, benzodiazepines) may be used for management of overt signs of excitement. If indicated, an appropriate parenteral cholinergic agent may be used as an antidote.

DOSAGE AND ADMINISTRATION

DOSAGE MUST BE ADJUSTED TO INDIVIDUAL PATIENT NEEDS.

The only oral dose clearly shown to be effective is 160 mg per day (in 4 equally divided doses). Since this dose is associated with a significant incidence of side effects, it is prudent to begin with 80 mg per day (in 4 equally divided doses). Depending upon the patient's response during the first week of therapy, the dose should be increased to 160 mg per day unless side effects limit dosage escalation.

If efficacy is not achieved within 2 weeks or side effects require doses below 80 mg per day, the drug should be discontinued. Documented safety data are not available for doses above 80 mg daily for periods longer than 2 weeks.

The intramuscular dosage form is to be used temporarily when the patient cannot take oral medication. Intramuscular injection is about twice as bioavailable as oral dosage forms; consequently, the recommended intramuscular dose is 80 mg daily (in 4 equally divided doses).

Oral Merispas Tablets (Dicyclomine Hydrochloride) should be started as soon as possible and the intramuscular form should not be used for periods longer than 1 or 2 days.

HOW SUPPLIED

Merispas Tablets Capsules USP and Merispas Tablets (Dicyclomine Hydrochloride) Tablets USP are supplied as follows:

10 mg capsules: Clear Dark Blue cap/Clear Dark Blue body hard gelatin capsules, imprinted with white ink WATSON over 794 on cap and 10 mg on the body, in bottles of 100 and 1000.

20 mg tablets: Blue, round, unscored, flat-faced, beveled-edge tablets, debossed WATSON and 795 on the periphery on one side and plain on the other side, in bottles of 100 and 1000.

Storage

Store at controlled room temperature 15°-30°C (59°-86°F).

Dispense in a well-closed container as defined in USP/NF.

Manufactured for:

Watson Laboratories, Inc.

Corona, CA 92880 USA

Manufactured by:

Patheon Pharmaceuticals Inc.

Cincinnati, OH 45215 USA

Mefenamic Acid:

• Indications and usage
• Contraindications
• Warnings
• Precautions
• Adverse reactions
• Overdosage
• Dosage and administration
• How supplied
• Merispas Tablets (Mefenamic Acid) reviews

INDICATIONS AND USAGE

Carefully consider the potential benefits and risks of Merispas Tablets (Mefenamic Acid) and other treatment options before deciding to use Merispas Tablets (Mefenamic Acid). Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS; Gastrointestinal Bleeding, Ulceration, and Perforation ).

Merispas Tablets (Mefenamic Acid) is indicated:

• For relief of mild to moderate pain in patients ≥ 14 years of age, when therapy will not exceed one week (7 days).
• For treatment of primary dysmenorrhea.

CONTRAINDICATIONS

Merispas Tablets (Mefenamic Acid) is contraindicated in the following patients:

• Known hypersensitivity (e.g., anaphylactic reactions and serious skin reactions) to Merispas Tablets (Mefenamic Acid) or any components of the drug product (see WARNINGS; Anaphylactic Reactions, Serious Skin Reactions).
• History of asthma, urticaria, or other allergic-type reactions after taking aspirin or other NSAIDs. Severe, sometimes fatal, anaphylactic reactions to NSAIDs have been reported in such patients (see WARNINGS; Anaphylactic Reaction, Exacerbation of Asthma Related to Aspirin Sensitivity).
• In the setting of coronary artery bypass graft (CABG) surgery (see WARNINGS; Cardiovascular Thrombotic Events ).

WARNINGS

Cardiovascular Thrombotic Events

Clinical trials of several COX-2 selective and nonselective NSAIDs of up to three years duration have shown an increased risk of serious cardiovascular thrombotic events, including myocardial infarction (MI) and stroke, which can be fatal. Based on available data, it is unclear that the risk for CV thrombotic events is similar for all NSAIDs. The relative increase in serious CV thrombotic events over baseline conferred by NSAID use appears to be similar in those with and without known CV disease or risk factors for CV disease. However, patients with known CV disease or risk factors had a higher absolute incidence of excess serious CV thrombotic events, due to their increased baseline rate. Some observational studies found that this increased risk of serious CV thrombotic events began as early as the first weeks of treatment. The increase in CV thrombotic risk has been observed most consistently at higher doses.

To minimize the potential risk for an adverse CV event in NSAID-treated patients, use the lowest effective dose for the shortest duration possible. Physicians and patients should remain alert for the development of such events throughout the entire treatment course, even in the absence of previous CV symptoms. Patients should be informed about the symptoms of serious CV events and the steps to take if they occur.

There is no consistent evidence that concurrent use of aspirin mitigates the increased risk of serious CV thrombotic events associated with NSAID use. The concurrent use of aspirin and an NSAID, such as Merispas Tablets (Mefenamic Acid), increases the risk of serious gastrointestinal (GI) events (see WARNINGS; Gastrointestinal Bleeding, Ulceration, and Perforation ).

Status Post Coronary Artery Bypass Graft (CABG) Surgery

Two large, controlled, clinical trials of a COX-2 selective NSAID for the treatment of pain in the first 10-14 days following CABG surgery found an increased incidence of myocardial infarction and stroke. NSAIDs are contraindicated in the setting of CABG (see CONTRAINDICATIONS).

Post-MI Patients

Observational studies conducted in the Danish National Registry have demonstrated that patients treated with NSAIDs in the post-MI period were at increased risk of reinfarction, CV-related death, and all-cause mortality beginning in the first week of treatment. In this same cohort, the incidence of death in the first year post-MI was 20 per 100 person years in NSAID-treated patients compared to 12 per 100 person years in non-NSAID exposed patients. Although the absolute rate of death declined somewhat after the first year post-MI, the increased relative risk of death in NSAID users persisted over at least the next four years of follow-up.

Avoid the use of Merispas Tablets in patients with a recent MI unless the benefits are expected to outweigh the risk of recurrent CV thrombotic events. If Merispas Tablets (Mefenamic Acid) is used in patients with a recent MI, monitor patients for signs of cardiac ischemia.

Gastrointestinal Bleeding, Ulceration, and Perforation

NSAIDs, including Merispas Tablets (Mefenamic Acid), cause serious gastrointestinal (GI) adverse events including inflammation, bleeding, ulceration, and perforation of the esophagus, stomach, small intestine, or large intestine, which can be fatal. These serious adverse events can occur at any time, with or without warning symptoms, in patients treated with NSAIDs. Only one in five patients who develop a serious upper GI adverse event on NSAID therapy is symptomatic. Upper GI ulcers, gross bleeding, or perforation caused by NSAIDs occur in approximately 1% of patients treated for 3-6 months, and in about 2-4% of patients treated for one year. However, even short-term NSAID therapy is not without risk.

Risk Factors for GI Bleeding, Ulceration, and Perforation

Patients with a prior history of peptic ulcer disease and/or GI bleeding who used NSAIDs had a greater than 10-fold increased risk for developing a GI bleed compared to patients without these risk factors. Other factors that increase the risk for GI bleeding in patients treated with NSAIDs include longer duration of NSAID therapy, concomitant use of oral corticosteroids, aspirin, anticoagulants, or selective serotonin reuptake inhibitors ; smoking, use of alcohol, older age, and poor general health status. Most postmarketing reports of fatal GI events occurred in elderly or debilitated patients. Additionally, patients with advanced liver disease and/or coagulopathy are at increased risk for GI bleeding.

Strategies to Minimize the GI Risks in NSAID-treated patients

• Use the lowest effective dosage for the shortest possible duration.
• Avoid administration of more than one NSAID at a time.
• Avoid use in patients at higher risk unless benefits are expected to outweigh the increased risk of bleeding. For such patients, as well as those with active GI bleeding, consider alternate therapies other than NSAIDs.
• Remain alert for signs and symptoms of GI ulceration and bleeding during NSAID therapy.
• If a serious GI adverse event is suspected, promptly initiate evaluation and treatment, and discontinue Merispas Tablets (Mefenamic Acid) until a serious GI adverse event is ruled out.
• In the setting of concomitant use of low-dose aspirin for cardiac prophylaxis, monitor patients more closely for evidence of GI bleeding (see PRECAUTIONS; Drug Interactions ).

Hepatotoxicity

Elevations of ALT or AST have been reported in approximately 1% of NSAID-treated patients in clinical trials. In addition, rare, sometimes fatal, cases of severe hepatic injury, including fulminant hepatitis, liver necrosis, and hepatic failure have been reported.

Elevations of ALT or AST (less than three times ULN) may occur in up to 15% of patients treated with NSAIDs including Merispas Tablets (Mefenamic Acid).

Inform patients of the warning signs and symptoms of hepatotoxicity (e.g., nausea, fatigue, lethargy, diarrhea, pruritus, jaundice, right upper quadrant tenderness, and "flu-like" symptoms). If clinical signs and symptoms consistent with liver disease develop, or if systemic manifestations occur (e.g., eosinophilia, rash, etc.), discontinue Merispas Tablets (Mefenamic Acid) immediately, and perform a clinical evaluation of the patient.

Hypertension

NSAIDs, including Merispas Tablets (Mefenamic Acid), can lead to new onset of hypertension or worsening of pre-existing hypertension, either of which may contribute to the increased incidence of CV events. Patients taking angiotensin converting enzyme (ACE) inhibitors, thiazides diuretics, or loop diuretics may have impaired response to these therapies when taking NSAIDs (see PRECAUTIONS; Drug Interactions ).

Monitor blood pressure (BP) during the initiation of NSAID treatment and throughout the course of therapy.

Heart Failure and Edema

The Coxib and traditional NSAID Trialists' Collaboration meta-analysis of randomized controlled trials demonstrated an approximately two-fold increase in hospitalizations for heart failure in COX-2 selective-treated patients and nonselective NSAID-treated patients compared to placebo-treated patients. In a Danish National Registry study of patients with heart failure, NSAID use increased the risk of MI, hospitalization for heart failure, and death.

Additionally, fluid retention and edema have been observed in some patients treated with NSAIDs. Use of Merispas Tablets may blunt the CV effects of several therapeutic agents used to treat these medical conditions (e.g., diuretics, ACE inhibitors, or angiotensin receptor blockers [ARBs]) (see PRECAUTIONS; Drug Interactions ).

Avoid the use of Merispas Tablets (Mefenamic Acid) in patients with severe heart failure unless the benefits are expected to outweigh the risk of worsening heart failure. If Merispas Tablets (Mefenamic Acid) is used in patients with severe heart failure, monitor patients for signs of worsening heart failure.

Renal Toxicity and Hyperkalemia

Renal Toxicity

Long-term administration of NSAIDs has resulted in renal papillary necrosis and other renal injury.

Renal toxicity has also been seen in patients in whom renal prostaglandins have a compensatory role in the maintenance of renal perfusion. In these patients, administration of an NSAID may cause a dose-dependent reduction in prostaglandin formation and, secondarily, in renal blood flow, which may precipitate overt renal decompensation. Patients at greatest risk of this reaction are those with impaired renal function, dehydration, hypovolemia, heart failure, liver dysfunction, those taking diuretics and ACE inhibitors or ARBs, and the elderly. Discontinuation of NSAID therapy is usually followed by recovery to the pretreatment state.

No information is available from controlled clinical studies regarding the use of Merispas Tablets in patients with advanced renal disease. The renal effects of Merispas Tablets (Mefenamic Acid) may hasten the progression of renal dysfunction in patients with pre-existing renal disease.

Correct volume status in dehydrated or hypovolemic patients prior to initiating Merispas Tablets (Mefenamic Acid). Monitor renal function in patients with renal or hepatic impairment, heart failure, dehydration, or hypovolemia during use of Merispas Tablets (Mefenamic Acid) (see PRECAUTIONS; Drug Interactions ). Avoid the use of Merispas Tablets (Mefenamic Acid) in patients with advanced renal disease unless the benefits are expected to outweigh the risk of worsening renal function. If Merispas Tablets (Mefenamic Acid) is used in patients with advanced renal disease, monitor patients for signs of worsening renal function.

Hyperkalemia

Increases in serum potassium concentration, including hyperkalemia, have been reported with use of NSAIDs, even in some patients without renal impairment. In patients with normal renal function, these effects have been attributed to a hyporeninemic-hypoaldosteronism state.

Anaphylactic Reactions

Merispas Tablets has been associated with anaphylactic reactions in patients with and without known hypersensitivity to Merispas Tablets (Mefenamic Acid) and in patients with aspirin-sensitive asthma (see CONTRAINDICATIONS , WARNINGS; Exacerbation of Asthma Related to Aspirin Sensitivity).

Seek emergency help if anaphylactic reaction occurs.

Exacerbation of Asthma Related to Aspirin Sensitivity

A subpopulation of patients with asthma may have aspirin-sensitive asthma which may include chronic rhinosinusitis complicated by nasal polyps; severe, potentially fatal bronchospasm; and/or intolerance to aspirin and other NSAIDs. Because cross-reactivity between aspirin and other NSAIDs has been reported in such aspirin-sensitive patients, Merispas Tablets (Mefenamic Acid) is contraindicated in patients with this form of aspirin sensitivity (see CONTRAINDICATIONS ). When Merispas Tablets (Mefenamic Acid) is used in patients with pre-existing asthma (without known aspirin sensitivity), monitor patients for changes in the signs and symptoms of asthma.

Serious Skin Reactions

NSAIDs, including Merispas Tablets, can cause serious skin adverse reactions such as exfoliative dermatitis, Stevens-Johnson Syndrome (SJS), and toxic epidermal necrolysis (TEN), which can be fatal. These serious events may occur without warning. Inform patients about the signs and symptoms of serious skin reactions and to discontinue the use of Merispas Tablets (Mefenamic Acid) at the first appearance of skin rash or any other sign of hypersensitivity. Merispas Tablets (Mefenamic Acid) is contraindicated in patients with previous serious skin reactions to NSAIDs (see CONTRAINDICATIONS ).

Premature Closure of Fetal Ducts Arteriosus

Merispas Tablets (Mefenamic Acid) may cause premature closure of the ductus arteriosus. Avoid use of NSAIDs, including Merispas Tablets (Mefenamic Acid), in pregnant women starting at 30 weeks of gestation (third trimester) (see PRECAUTIONS; Pregnancy ).

Hematological Toxicity

Anemia has occurred in NSAID-treated patients. This may be due to occult or gross blood loss, fluid retention, or an incompletely described effect on erythropoiesis. If a patient treated with Merispas Tablets (Mefenamic Acid) has any signs or symptoms of anemia, monitor hemoglobin or hematocrit.

NSAIDs, including Merispas Tablets (Mefenamic Acid), may increase the risk of bleeding events. Co-morbid conditions such as coagulation disorders or concomitant use of warfarin, other anticoagulants, antiplatelet agents (e.g., aspirin), serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) may increase this risk. Monitor these patients for signs of bleeding .

PRECAUTIONS

General

Merispas Tablets cannot be expected to substitute for corticosteroids or to treat corticosteroid insufficiency. Abrupt discontinuation of corticosteroids may lead to disease exacerbation.. Patients on prolonged corticosteroid therapy should have their therapy tapered slowly if a decision is made to discontinue corticosteroids.

Information for Patients

Advise the patient to read the FDA-approved patient labeling (Medication Guide) that accompanies each prescription dispensed. Inform patients, families and their caregivers of the following information before initiating therapy with Merispas Tablets (Mefenamic Acid) and periodically during the course of ongoing therapy.

Cardiovascular Thrombotic Events

Advise patients to be alert for the symptoms of cardiovascular thrombotic events, including chest pain, shortness of breath, weakness, or slurring of speech, and to report any of these symptoms to their healthcare provider immediately.

Gastrointestinal Bleeding, Ulceration, and Perforation

Advise patients to report symptoms of ulcerations and bleeding, including epigastric pain, dyspepsia, melena, and hematemesis to their healthcare provider. In the setting of concomitant use of low-dose aspirin for cardiac prophylaxis, inform patients of the increased risk for and the signs and symptoms of GI bleeding (see WARNINGS; Gastrointestinal Bleeding, Ulceration, and Perforation).

Hepatotoxicity

Inform patients of the warning signs and symptoms of hepatotoxicity. If these occur, instruct patients to stop Merispas Tablets (Mefenamic Acid) and seek immediate medical therapy (see WARNINGS; Hepatotoxicity ).

Heart Failure and Edema

Advise patients to be alert for the symptoms of congestive heart failure including shortness of breath, unexplained weight gain, or edema and to contact their healthcare provider if such symptoms occur (see WARNINGS; Heart Failure and Edema ).

Anaphylactic Reactions

Inform patients of the signs of an anaphylactic reaction. Instruct patients to seek immediate emergency help if these occur (see CONTRAINDICATIONS, WARNINGS; Anaphylactic Reactions ).

Serious Skin Reactions

Advise patients to stop Merispas Tablets (Mefenamic Acid) immediately if they develop any type of rash and contact their healthcare provider as soon as possible (see WARNINGS; Serious Skin Reactions ).

Female Fertility

Advise females of reproductive potential who desire pregnancy that NSAIDs, including Merispas Tablets, may be associated with a reversible delay in ovulation. .

Fetal Toxicity

Inform pregnant women to avoid use of Merispas Tablets (Mefenamic Acid) and other NSAIDs starting at 30 weeks gestation because of the risk of the premature closure of the fetal ductus arteriosus (see WARNINGS; Premature Closure of Fetal Ductus Arteriosus ).

Avoid Concomitant Use of NSAIDs

Inform patients that the concomitant use of Merispas Tablets with other NSAIDs or salicylates (e.g., diflunisal, salsalate) is not recommended due to the increased risk of gastrointestinal toxicity, and little or no increase in efficacy (see WARNINGS; Gastrointestinal Bleeding, Ulceration and Perforation, PRECAUTIONS; Drug Interactions ). Alert patients that NSAIDs may be present in "over the counter" medications for treatment of colds, fever, or insomnia.

Use of NSAIDS and Low-Dose Aspirin

Inform patients not to use low-dose aspirin concomitantly with Merispas Tablets (Mefenamic Acid) until they talk to their healthcare provider .

Masking of Inflammation and Fever

The pharmacological activity of Merispas Tablets in reducing inflammation, and possibly fever, may diminish the utility of diagnostic signs in detecting infections.

Laboratory Monitoring

Because serious GI bleeding, hepatotoxicity, and renal injury can occur without warning symptoms or signs, consider monitoring patients on long-term NSAID treatment with a CBC and a chemistry profile checked periodically (see WARNINGS; Gastrointestinal Bleeding, Ulceration and Perforation, and Hepatotoxicity ).

Drug Interactions

Drug/Laboratory Test Interactions

Merispas Tablets (Mefenamic Acid) may prolong prothrombin time. Therefore, when the drug is administered to patients receiving oral anticoagulant drugs, frequent monitoring of prothrombin time is necessary.

A false-positive reaction for urinary bile, using the diazo tablet test, may result after Merispas Tablets (Mefenamic Acid) administration. If biliuria is suspected, other diagnostic procedures, such as the Harrison spot test, should be performed.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

Long-term studies in animals to evaluate the carcinogenic potential of Merispas Tablets have not been conducted.

Mutagenesis

Studies to evaluate the mutagenic potential of Merispas Tablets (Mefenamic Acid) have not been completed.

Impairment of Fertility

Dietary administration of Merispas Tablets to male rats 61 days- and to female rats 15 days- prior to mating through to Gestation Day (GD) 21 at a dose of 155 mg/kg/day (equivalent to the Maximum Recommended Human Dose [MRHD] of 1500 mg/day on a mg/m² basis) resulted in decreased corpora lutea.

In another study, rats administered up to 10-times a human dose of 250 mg showed decreased fertility.

Pregnancy

Risk Summary

Use of NSAIDs, including Merispas Tablets, during the third trimester of pregnancy increases the risk of premature closure of the fetal ductus arteriosus. Avoid use of NSAIDs, including Merispas Tablets (Mefenamic Acid), in pregnant women starting at 30 weeks of gestation (third trimester) .

There are no adequate and well-controlled studies of Merispas Tablets (Mefenamic Acid) in pregnant women.

Data from observational studies regarding potential embryofetal risks of NSAID use in women in the first or second trimesters of pregnancy are inconclusive. In the general U.S. population, all clinically recognized pregnancies, regardless of drug exposure, have a background rate of 2-4% for major malformations, and 15-20% for pregnancy loss. In animal reproduction studies in rats and rabbits when dosed throughout gestation, there were no evidence of developmental effects at a dose of Merispas Tablets (Mefenamic Acid) 1.6-times and 0.6-times the maximum recommended human dose (MRHD), respectively. Dietary administration of Merispas Tablets (Mefenamic Acid) at a dose 1.2-times the MRHD from gestation day (GD) 15 to weaning or at a dose equivalent to the MRHD from 15 days prior to mating through to weaning resulted in greater incidences of perinatal death . Based on animal data, prostaglandins have been shown to have an important role in endometrial vascular permeability, blastocyst implantation, and decidualization. In animal studies, administration of prostaglandin synthesis inhibitors such as Merispas Tablets (Mefenamic Acid), resulted in increased pre- and post-implantation loss.

Data

Animal data

Pregnant rats administered 249 mg/kg of Merispas Tablets (1.6-times the MRHD of 1500 mg/day on a mg/m² basis) from GD 6 to GD 15 did not result in any clear adverse developmental effects.

Pregnant rabbits given 50 mg/kg of Merispas Tablets (Mefenamic Acid) (0.6-times the MRHD on a mg/m² basis) from GD 6 to GD 18 did not result in any clear treatment-related adverse developmental effects. However, incidences of resorption were greater in treated compared to control animals. This dose was associated with some evidence of maternal toxicity with 4 of 18 rabbits exhibiting diarrhea and weight loss.

Dietary administration of Merispas Tablets (Mefenamic Acid) at a dose of 181 mg/kg (1.2-times the MRHD on a mg/m² basis) to pregnant rats from GD 15 to weaning resulted in an increased incidence of perinatal death. Treated dams were associated with decreased weight gain and delayed parturition. In another study, dietary administration of Merispas Tablets (Mefenamic Acid) at a dose of 155 mg/kg (equivalent to the MRHD of 1500 mg/day on a mg/m² basis) to females 15 days prior to mating through to weaning resulted in smaller average litter sizes and higher incidence of perinatal death.

Labor and Delivery

In rat studies with NSAIDs, as with other drugs known to inhibit prostaglandin synthesis, an increased incidence of dystocia, delayed parturition, decreased pup survival occurred and increased the incidence of stillbirth. The effects of Merispas Tablets (Mefenamic Acid) on labor and delivery in pregnant women are unknown.

Nursing Mothers

Trace amounts of Merispas Tablets may be present in breast milk and transmitted to the nursing infant. Because of the potential for serious adverse reactions in nursing infants from Merispas Tablets (Mefenamic Acid), a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Infertility

Females

Based on the mechanism of action, the use of prostaglandin-mediated NSAIDs, including Merispas Tablets may delay or prevent rupture of ovarian follicles, which has been associated with reversible infertility in some women. Published animal studies have shown that administration of prostaglandin synthesis inhibitors has the potential to disrupt prostaglandin in mediated follicular rupture required for ovulation. Small studies in women treated with NSAIDs have also shown a reversible delay in ovulation. Consider withdrawal of NSAIDs, including Merispas Tablets (Mefenamic Acid), in women who have difficulties conceiving or who are undergoing investigation of infertility.

Pediatric Use

Safety and effectiveness in pediatric patients below the age of 14 have not been established.

Geriatric Use

Elderly patients, compared to younger patients, are at greater risk for NSAID-associated serious cardiovascular, gastrointestinal, and/or renal adverse reactions. If the anticipated benefit for the elderly patient outweighs these potential risks, start dosing at the low end of the dosing range, and monitor patients for adverse effects .

Clinical studies of Merispas Tablets (Mefenamic Acid) did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. As with any NSAID, caution should be exercised in treating the elderly (65 years and older).

This drug 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 (See CLINICAL PHARMACOLOGY, ADVERSE REACTIONS ).

ADVERSE REACTIONS

The following adverse reactions are discussed in greater detail in other sections of the labeling:

• Cardiovascular Thrombotic Events
• GI Bleeding, Ulceration and Perforation (see WARNINGS)
• Hepatotoxicity (see WARNINGS)
• Hypertension (see WARNINGS)
• Heart Failure and Edema (see WARNINGS))
• Renal Toxicity and Hyperkalemia (see WARNINGS )
• Anaphylactic Reactions (see WARNINGS)
• Serious Skin Reactions (see WARNINGS)
• Hematologic Toxicity (see WARNINGS)

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

In patients taking Merispas Tablets (Mefenamic Acid) or other NSAIDs, the most frequently reported adverse experiences occurring in approximately 1-10% of patients are:

Gastrointestinal experiences including - abdominal pain, constipation, diarrhea, dyspepsia, flatulence, gross bleeding/perforation, heartburn, nausea, GI ulcers (gastric/duodenal), vomiting, abnormal renal function, anemia, dizziness, edema, elevated liver enzymes, headaches, increased bleeding time, pruritus, rashes, tinnitus

Additional adverse experiences reported occasionally and listed here by body system include:

Body as a whole - fever, infection, sepsis

Cardiovascular system - congestive heart failure, hypertension, tachycardia, syncope

Digestive system - dry mouth, esophagitis, gastric/peptic ulcers, gastritis, gastrointestinal bleeding, glossitis, hematemesis, hepatitis, jaundice

Hemic and lymphatic system - ecchymosis, eosinophilia, leukopenia, melena, purpura, rectal bleeding, stomatitis, thrombocytopenia

Metabolic and nutritional - weight changes

Nervous system - anxiety, asthenia, confusion, depression, dream abnormalities, drowsiness; insomnia, malaise, nervousness, paresthesia, somnolence, tremors, vertigo

Respiratory system - asthma, dyspnea

Skin and appendages - alopecia, photosensitivity, pruritus, sweat

Special senses - blurred vision

Urogenital system - cystitis, dysuria, hematuria, interstitial nephritis, oliguria/polyuria, proteinuria, renal failure

Other adverse reactions, which occur rarely are:

Body as a whole - anaphylactoid reactions, appetite changes, death

Cardiovascular system - arrhythmia, hypotension, myocardial infarction, palpitations, vasculitis

Digestive system - eructation, liver failure, pancreatitis

Hemic and lymphatic system - agranulocytosis, hemolytic anemia, aplastic anemia, lymph-adenopathy, pancytopenia

Metabolic and nutritional - hyperglycemia

Nervous system - convulsions, coma, hallucinations, meningitis

Respiratory - respiratory depression, pneumonia

Skin and appendages - angioedema, toxic epidermal necrosis, erythema multiforme, exfoliative dermatitis, Stevens-Johnson syndrome, urticaria

Special senses - conjunctivitis, hearing impairment

OVERDOSAGE

Symptoms following acute NSAID overdosages have been typically limited to lethargy, drowsiness, nausea, vomiting, and epigastric pain, which have been generally reversible with supportive care. Gastrointestinal bleeding has occurred. Hypertension, acute renal failure, respiratory depression and coma have occurred, but were rare .

Manage patients with symptomatic and supportive care following an NSAID overdosage. There are no specific antidotes. Consider emesis and/or activated charcoal (60 to 100 grams in adults, 1 to 2 grams per kg of body weight in pediatric patients) and/or osmotic cathartic in symptomatic patients seen within four hours of ingestion or in patients with a large overdose (5 to 10 times the recommended dosage). Forced diuresis, alkalinization of urine, hemodialysis, or hemoperfusion may not be useful due to high protein binding.

For additional information about overdosage treatment, contact a poison control center (1-800-222-1222).

DOSAGE AND ADMINISTRATION

Carefully consider the potential benefits and risks of Merispas Tablets (Mefenamic Acid) and other treatment options before deciding to use Merispas Tablets (Mefenamic Acid). Use the lowest effective dose for the shortest duration consistent with individual patient treatment goals (see WARNINGS; Gastrointestinal Bleeding, Ulceration, and Perforation ).

After observing the response to initial therapy with Merispas Tablets (Mefenamic Acid), the dose and frequency should be adjusted to suit an individual patient's needs.

For the relief of acute pain in adults and adolescents ≥14 years of age, the recommended dose is 500 mg as an initial dose followed by 250 mg every 6 hours as needed, usually not to exceed one week.

For the treatment of primary dysmenorrhea, the recommended dose is 500 mg as an initial dose followed by 250 mg every 6 hours, given orally, starting with the onset of bleeding and associated symptoms. Clinical studies indicate that effective treatment can be initiated with the start of menses and should not be necessary for more than 2 to 3 days.

HOW SUPPLIED

Merispas Tablets (mefenamic acid) is available as 250 mg blue-banded, ivory capsules, imprinted with " FHPC 400" and "PONSTEL^®".

Dispense in a tight container as defined in the USP.

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Storage

Store at room temperature 20° to 25°C (68°to 77°F); excursions permitted to 15° to 30°C (59° to 86°F).

Manufactured for:

Shionogi Inc.

Florham Park, NJ 07932

Manufactured by:

Halo Pharmaceutical Inc.

Whippany, NJ 07981

Rev. 05/2016

For inquires call 1-800-849-9707

NDC 59630-400-30

Merispas Tablets (Mefenamic Acid)^®

(Mefenamic Acid Capsules, USP)

250 mg

Rx Only

30 CAPSULES

PHARMACIST: PLEASE DISPENSE

WITH MEDICATION GUIDE

SHIONOGI INC.