Pilocarpine Tablets

Name: Pilocarpine Tablets

Pilocarpine Hydrochloride Tablets, USP

Rx Only

Pilocarpine Tablets Description

Pilocarpine hydrochloride tablets, USP contain pilocarpine hydrochloride, a cholinergic agonist for oral use. Pilocarpine hydrochloride, USP is a hygroscopic, odorless, bitter tasting white crystal or powder, which is soluble in water and alcohol and virtually insoluble in most non-polar solvents. Pilocarpine hydrochloride, USP with a chemical name of (3S-cis)-2(3H)-Furanone, 3-ethyldihydro-4-[(1-methyl-1H-imidazol-5-yl) methyl] monohydrochloride, has a molecular weight of 244.72.

Each 5 mg Pilocarpine Hydrochloride Tablet, USP for oral administration contains 5 mg of pilocarpine hydrochloride. Inactive ingredients in the tablet are microcrystalline cellulose and stearic acid, the tablet’s film coating is: polyvinyl alcohol, titanium dioxide, polyethylene glycol, and talc.

Each 7.5 mg Pilocarpine Hydrochloride Tablet, USP for oral administration contains 7.5 mg of pilocarpine hydrochloride. Inactive ingredients in the tablet are microcrystalline cellulose and stearic acid, the tablet’s film coating is: FD&C Blue #2/Indigo Carmine aluminum lake, polyvinyl alcohol, titanium dioxide, polyethylene glycol, and talc.

Indications and usage

Pilocarpine hydrochloride tablets, USP are indicated for 1) the treatment of symptoms of dry mouth from salivary gland hypofunction caused by radiotherapy for cancer of the head and neck; and 2) the treatment of symptoms of dry mouth in patients with Sjogren’s syndrome.

Precautions

General

Pilocarpine toxicity is characterized by an exaggeration of its parasympathomimetic effects. These may include: headache, visual disturbance, lacrimation, sweating, respiratory distress, gastrointestinal spasm, nausea, vomiting, diarrhea, atrioventricular block, tachycardia, bradycardia, hypotension, hypertension, shock, mental confusion, cardiac arrhythmia, and tremors.

The dose-related cardiovascular pharmacologic effects of pilocarpine include hypotension, hypertension, bradycardia, and tachycardia.

Pilocarpine should be administered with caution to patients with known or suspected cholelithiasis or biliary tract disease. Contractions of the gallbladder or biliary smooth muscle could precipitate complications including cholecystitis, cholangitis, and biliary obstruction.

Pilocarpine may increase ureteral smooth muscle tone and could theoretically precipitate renal colic (or “ureteral reflux”), particularly in patients with nephrolithiasis.

Cholinergic agonists may have dose-related central nervous system effects. This should be considered when treating patients with underlying cognitive or psychiatric disturbances.

Hepatic Insufficiency
Based on decreased plasma clearance observed in patients with moderate hepatic impairment, the starting dose in these patients should be 5 mg twice daily, followed by adjustment based on therapeutic response and tolerability. Patients with mild hepatic insufficiency (Child-Pugh score of 5-6) do not require dosage reductions. To date, pharmacokinetic studies in subjects with severe hepatic impairment (Child-Pugh score of 10-15) have not been carried out. The use of pilocarpine in these patients is not recommended.

Child-Pugh scoring system for Hepatic Impairment
Clinical and Biochemical
Measurements
Points Scored for
Increasing Abnormality
1 2 3
Encephalopathy (grade)* None 1 and 2 3 and 4
Ascites Absent Slight Moderate
Bilirubin (mg. per 100 ml.) 1-2 2-3 >3
Albumin (g. per 100 ml.) 3-5 2.8-3.5 <2.8
Prothrombin time (sec. Prolonged) 1-4 4-6 >6
For primary biliary cirrhosis:-
Bilirubin (mg. per 100 ml.)
1-4 4-10 >10

*According to grading of Trey C, Burns D, and Saunders S. Treatment of hepatic coma by exchange blood transfusion. N Engl J Med. 1966; 274:473-481.

Reference: Pugh, RNH, Murray-Lyon, IM, Dawson, JL Pietroni, MC, Williams, R. Transection of the oesophagus for bleeding oesophageal varices, Brit. J. Surg. 1973;60:646-9.

Information for Patients

Patients should be informed that pilocarpine may cause visual disturbances, especially at night, that could impair their ability to drive safely.

If a patient sweats excessively while taking pilocarpine hydrochloride and cannot drink enough liquid, the patient should consult a physician. Dehydration may develop.

Drug Interactions

Pilocarpine should be administered with caution to patients taking beta adrenergic antagonists because of the possibility of conduction disturbances. Drugs with parasympathomimetic effects administered concurrently with pilocarpine would be expected to result in additive pharmacologic effects.

Pilocarpine might antagonize the anticholinergic effects of drugs used concomitantly. These effects should be considered when anticholinergic properties may be contributing to the therapeutic effect of concomitant medication (e.g., atropine, inhaled ipratropium).

While no formal drug interaction studies have been performed, the following concomitant drugs were used in at least 10% of patients in either or both Sjogren’s efficacy studies: acetylsalicylic acid, artificial tears, calcium, conjugated estrogens, hydroxychloroquine sulfate, ibuprofen, levothyroxine sodium, medroxyprogesterone acetate, methotrexate, multivitamins, naproxen, omeprazole, paracetamol, and prednisone.

Carcinogenesis, Mutagenesis, Impairment of Fertility

Lifetime oral carcinogenicity studies were conducted in CD-1 mice and Sprague-Dawley rats. Pilocarpine did not induce tumors in mice at any dosage studied (up to 30 mg/kg/day, which yielded a systemic exposure approximately 50 times larger than the maximum systemic exposure observed clinically). In rats, a dosage of 18 mg/kg/day, which yielded a systemic exposure approximately 100 times larger than the maximum systemic exposure observed clinically, resulted in a statistically significant increase in the incidence of benign pheochromocytomas in both males and females, and a statistically significant increase in the incidence of hepatocellular adenomas in female rats. The tumorigenicity observed in rats was observed only at a large multiple of the maximum labeled clinical dose, and may not be relevant to clinical use.

No evidence that pilocarpine has the potential to cause genetic toxicity was obtained in a series of studies that included:
1) bacterial assays (Salmonella and E. coli) for reverse gene mutations; 2) an in vitro chromosome aberration assay in a Chinese hamster ovary cell line; 3) an in vivo chromosome aberration assay (micronucleus test) in mice; and 4) a primary DNA damage assay (unscheduled DNA synthesis) in rat hepatocyte primary cultures.

Oral administration of pilocarpine to male and female rats at a dosage of 18 mg/kg/day, which yielded a systemic exposure approximately 100 times larger than the maximum systemic exposure observed clinically, resulted in impaired reproductive function, including reduced fertility, decreased sperm motility, and morphologic evidence of abnormal sperm. It is unclear whether the reduction in fertility was due to effects on male animals, female animals, or both males and females. In dogs, exposure to pilocarpine at a dosage of 3 mg/kg/day (approximately 3 times the maximum recommended human dose when compared on the basis of body surface area (mg/m2) estimates) for six months resulted in evidence of impaired spermatogenesis. The data obtained in these studies suggest that pilocarpine may impair the fertility of male and female humans. Pilocarpine hydrochloride tablets should be administered to individuals who are attempting to conceive a child only if the potential benefit justifies potential impairment of fertility.

Pregnancy

Teratogenic effects

Pregnancy Category C

Pilocarpine was associated with a reduction in the mean fetal body weight and an increase in the incidence of skeletal variations when given to pregnant rats at a dosage of 90 mg/kg/day (approximately 26 times the maximum recommended dose for a 50 kg human when compared on the basis of body surface area (mg/m2) estimates). These effects may have been secondary to maternal toxicity. In another study, oral administration of pilocarpine to female rats during gestation and lactation at a dosage of 36 mg/kg/day (approximately 10 times the maximum recommended dose for a 50 kg human when compared on the basis of body surface area (mg/m2) estimates) resulted in an increased incidence of stillbirths; decreased neonatal survival and reduced mean body weight of pups were observed at dosages of 18 mg/kg/day (approximately 5 times the maximum recommended dose for a 50 kg human when compared on the basis of body surface area (mg/m2) estimates) and above. There are no adequate and well-controlled studies in pregnant women. Pilocarpine hydrochloride tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from pilocarpine hydrochloride tablets, 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.

Pediatric Use

Safety and effectiveness in pediatric patients have not been established.

Geriatric Use

Head and Neck Cancer Patients

In the placebo-controlled clinical trials (see Clinical Studies section) the mean age of patients was approximately 58 years (range 19 to 80). Of these patients, 97/369 (61/217 receiving pilocarpine) were over the age of 65 years. In the healthy volunteer studies, 15/150 subjects were over the age of 65 years. In both study populations, the adverse events reported by those over 65 years and those 65 years and younger were comparable. Of the 15 elderly volunteers (5 women, 10 men), the
5 women had higher Cmax and AUC’s than the men. (See Pharmacokinetics section.)

Sjogren’s Syndrome Patients

In the placebo-controlled clinical trials (see Clinical Studies section), the mean age of patients was approximately 55 years (range 21 to 85). The adverse events reported by those over 65 years and those 65 years and younger were comparable except for notable trends for urinary frequency, diarrhea, and dizziness (see ADVERSE REACTIONS section).

Principal display panel

NDC 10135-0589-01
Pilocarpine
Hydrochloride
Tablets, USP
5 mg
Rx Only
100 TABLETS

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