- Tablets: 10, 20, and 40 mg.
- Tablets (Chewable): 10 and 20 mg.
- Suspension: 40 mg per 5 ml (teaspoon). Injection: 10 mg/ml.
DRUG INTERACTIONS: Famotidine, like other drugs that reduce stomach acid, may interfere with the absorption of drugs that require acid for adequate absorption. Examples include iron salts (for example iron sulphate), itraconazole (Sporanox), and ketoconazole (Nizoral, Extina, Xolegel, Kuric).
PREGNANCY AND BREASTFEEDING SAFETY: Use of famotidine during pregnancy has not been adequately evaluated.
Famotidine is secreted into breast milk. Due to the potential but unknown harm that famotidine might cause to the infant, nursing mothers should consider discontinuing famotidine.
STORAGE: Tablets and suspension should be stored at room temperature, 15 C - 30 C (59 F - 86 F). Injection should be stored between 2 C - 8 C (36 F - 46 F).
DOSING: The recommended adult oral dose for treating duodenal ulcers is 40 mg once daily at bedtime or 20 mg twice daily. Most patients heal their ulcers within 4 weeks. The regimen for maintenance therapy after the ulcers are healed is 20 mg once a day at bedtime. The recommended oral dose for adults with gastric ulcers is, 40 mg once daily at bedtime.
Esophagitis is treated with 20 or 40 mg twice daily for up to 12 weeks. Zollinger-Ellison syndrome is treated with 20 mg every 6 hours, and doses up to 160 mg every 6 hours have been used in some patients.
GERD is treated with 20 mg twice daily for up to 6 weeks. Occasional heartburn is treated with 10-20 mg daily administered 15 to 60 minutes before ingestion of food or beverages that cause heartburn.
DRUG CLASS AND MECHANISM: Famotidine is an oral drug that blocks the production of acid by acid-producing cells in the stomach. It belongs to a class of drugs called H2 (histamine-2) blockers that also includes cimetidine (Tagamet), nizatidine (Axid), and ranitidine (Zantac). Histamine is a naturally-occurring chemical that stimulates cells in the stomach (parietal cells) to produce acid. H2-blockers inhibit the action of histamine on the cells, thus reducing the production of acid. Since excessive stomach acid can damage the esophagus, stomach, and duodenum and lead to inflammation and ulceration, reducing stomach acid prevents and heals acid-induced inflammation and ulcers. Famotidine was approved by the FDA in November 1986.
Medically reviewed by Eni Williams, PharmD, PhD
Reference: FDA Prescribing Information
Quick GuideHeartburn Causes, Symptoms, Remedies, and Treatments
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Need help identifying pills and medications?
Use the pill identifier tool on RxList.