Famotidine Dosage & Rx Info | Uses, Side Effects

Famotidine Generic Name & Formulations

Legal Class

General Description

Famotidine 20mg, 40mg; tabs.

Pharmacological Class

H₂ blocker.

How Supplied

Contact supplier

Manufacturer

Various generic manufacturers

Mechanism of Action

Famotidine is a competitive inhibitor of histamine-2 (H2) receptors. The primary clinically important pharmacologic activity of famotidine is inhibition of gastric secretion. Both the acid concentration and volume of gastric secretion are suppressed by famotidine, while changes in pepsin secretion are proportional to volume output.

Famotidine Indications

Indications

Active duodenal ulcer. Reduction of the risk duodenal ulcer recurrence in adults. Active gastric ulcer. Symptomatic nonerosive gastroesophageal reflux disease (GERD). Erosive esophagitis (EE). Pathological hypersecretory conditions (eg, Zollinger-Ellison syndrome, multiple endocrine adenomas) in adults.

Famotidine Dosage and Administration

Adults and Children

<40kg: use other oral forms. ≥40kg: Duodenal ulcer: 40mg once daily at bedtime or 20mg twice daily for up to 8 weeks. Recurrence: 20mg once daily at bedtime for up to 1 year or as clinically indicated. Gastric ulcer: 40mg once daily at bedtime for up to 8 weeks. GERD: 20mg twice daily for up to 6 weeks. EE: 20mg or 40mg twice daily for up to 12 weeks. Hypersecretory conditions: initially 20mg every 6hrs; individualize; max 160mg every 6hrs. Renal impairment: see full labeling.

Famotidine Contraindications

Contraindications

History of serious hypersensitivity reactions to H₂ receptor antagonists.

Famotidine Boxed Warnings

Not Applicable

Famotidine Warnings/Precautions

Warnings/Precautions

Symptomatic response does not preclude gastric malignancy; evaluate prior to initiation. Moderate to severe renal impairment (CrCl <50mL/min): reduce to ½ the dose or prolong dosing interval to 36–48hrs. Elderly: use low doses. Pregnancy. Nursing mothers.

Famotidine Pharmacokinetics

Metabolism

Hepatic.

Elimination

Renal (65-70%). Half-life: 2.5–3.5 hours.

Famotidine Interactions

Interactions

Concomitant dasatinib, delavirdine mesylate, cefditoren, fosamprenavir: not recommended. May alter absorption of pH-dependent drugs (eg, atazanavir, erlotinib, ketoconazole, itraconazole, ledipasvir/sofosbuvir, nilotinib, rilpivirine). May potentiate CYP1A2 substrates (eg, tizanidine); avoid; if necessary, monitor for hypotension, bradycardia, drowsiness. May give antacids concomitantly.

Famotidine Adverse Reactions

Adverse Reactions

Headache, dizziness, constipation, diarrhea, inj site reactions; rare: CNS reactions, prolonged QT interval in renal impairment (moderate and severe).

Famotidine Clinical Trials

See Literature

Famotidine Note

Notes

Formerly known under the brand name Pepcid.

Famotidine Patient Counseling