Famotidine

Innovator's Monograph

Pharmacology

Famotidine lowers the excess acid secretion by blocking the histamine (H2) receptor and thus accelerates the ulcer healing process in the stomach. This suppresses stimulated acid output within two hours after administration for 12 hours. The affinity of Famotidine for the H2 receptor is significantly greater than those of Ranitidine or Cimetidine. Famotidine has no anti-androgenic activity and has no action on hepatic cytochrome P450 activity.

Uses of Famotidine

Famotidine is indicated for-

Duodenal ulcers,
Gastric ulcers,
Prophylaxis of duodenal ulcer relapse,
Gastroesophageal reflux disease, and
Zollinger-Ellison syndrome.

Dosage and Administration

Route of administration: Orally. Adult Dose:

In gastric and duodenal ulcer: Famotidine 40 mg at night.
Duodenal ulcer: The recommended initial dose is 40 mg Famotidine at night. Treatment should be continued for four to eight weeks. In most patients, healing occurs on this regimen within four weeks. In those patients whose ulcers have not entirely healed after four weeks, a further four-week period of treatment is recommended.
Maintenance therapy: For preventing the recurrence of duodenal ulceration, a reduced dose of 20 mg Famotidine at night is recommended. This 20 mg maintenance dose has been continued effectively in clinical studies for 12 months.
Gastric ulcer: The recommended dose is 40 mg Famotidine at night. Treatment should be continued for four to eight weeks unless endoscopy reveals earlier healing.
Gastroesophageal Reflux Disease (GERD):
Symptomatic: 20 mg b.i.d
Erosive: 40 mg b.i.d
Maintenance Dose: 20 mg b.i.d
Zollinger-Ellison Syndrome: Patients without prior antisecretory therapy should be started on 20 mg Famotidine every six hours. The dosage should then be adjusted to individual responses. Dosage of up to 40 mg daily in divided doses has been used for up to one year without the development of significant adverse effects. Patients receiving another H2 -antagonist may be switched directly to Famotidine at a dose higher than that recommended few cases. The starting dose will depend on the severity of the condition and the last dose of H2 -antagonist previously used.
Dosage adjustment in renal impairment: Since Famotidine is excreted primarily by the kidney; caution should be observed in patients with impaired renal function. A reduction in daily doses should be considered if creatinine clearance falls to or below 30 ml/min, the dose should be reduced to 20 mg per day.

Child Dose: Gastroesophageal Reflux Disease (GERD):

Less than 3 months: 0.5 mg/kg once daily for up to 8 weeks.
3 months to less than 1 year: 0.5 mg/kg orally 2 times a day for up to 8 weeks.
1 year to 16 years: 1 mg/kg/day orally 2 times a day.

Maximum Dose: Up to 40 mg/dose. Dyspepsia: 0.5 mg/kg orally once daily. Peptic ulcer: 0.5 mg/kg orally once daily or divided twice daily up to 40 mg/day. Dosage can be administered irrespective of meals. Antacids may be given concomitantly if needed. OR AS DIRECTED BY THE PHYSICIAN.

Contradiction

This drug is contraindicated in patients hypersensitive to Famotidine.

Precaution and Warning

Famotidine should be used carefully if the following condition exists:

Renal impairment.
Malignancy.

Interaction

With Medicine: Antacids slightly decrease the bioavailability of Famotidine. May reduce serum concentration of ketoconazole and itraconazole. With food & others: Avoid Alcohol and limit Caffeine intake.

Side Effects of Famotidine

Common side effects:

Headache,
Dizziness,
Constipation,
Diarrhea,
Dryness of mouth,
Nausea,
Skin rash,
Intestinal disturbance,
Anorexia and
Fatigue.

Rare side effects:

Impotence and
Gynecomastia.

Use in Pregnancy & Lactation

Pregnancy: Pregnancy Category B. There are no adequate or well-controlled studies on pregnant women but potential benefits may warrant the use of the drug in pregnant women despite potential risks. Lactation: Famotidine is detectable in human breast milk. The decision should be made whether to discontinue nursing or discontinue the drug, considering the importance of the drug to the mother.