Famotidine

What it is and how it works

Mechanism of Action Famotidine is a competitive inhibitor of histamine-2 (H 2 ) 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.

Mechanism class: Histamine H2 Receptor Antagonists

Indications

Famotidine for oral suspension is indicated in adults for the treatment of: active duodenal ulcer (DU). active gastric ulcer (GU). symptomatic nonerosive gastroesophageal reflux disease (GERD). erosive esophagitis due to GERD, diagnosed by biopsy. treatment of pathological hypersecretory conditions (e.g., Zollinger-Ellison syndrome, multiple endocrine neoplasias). reduction of the risk of duodenal ulcer recurrence. Famotidine for oral suspension is indicated in pediatric patients 1 year of age and older for the treatment of: peptic ulcer disease. GERD with or without esophagitis and ulcerations. Famotidine for oral suspension is indicated in pediatric patients from birth to less than 1 year of age for the treatment of: GERD. Famotidine for oral suspension is a histamine-2 (H2) receptor antagonist indicated : In adults for the treatment of: active duodenal ulcer (DU). active gastric ulcer (GU). symptomatic nonerosive gastroesophageal reflux disease (GERD). erosive esophagitis due to GERD, diagnosed by biopsy.

Dosage and administration (summary)

Recommended adult dosage by indication : Active DU 40 mg once daily; or 20 mg twice daily Active GU 40 mg once daily Symptomatic Nonerosive GERD 20 mg twice daily Erosive Esophagitis due to GERD 20 mg twice daily; or 40 mg twice daily Pathological Hypersecretory Conditions 20 mg every 6 hours; adjust to patient needs; maximum 160 mg every 6 hours Risk Reduction of DU Recurrence 20 mg once daily Recommended pediatric dosage by indication : Peptic Ulcer Disease 1 year to less than 17 years Starting dosage 0.5 mg/kg once daily; or 0.25 mg/kg twice daily; may increase to 1 mg/kg once daily at bedtime or 0.5 mg/kg twice daily.

Contraindications

Famotidine for oral suspension is contraindicated in patients with a history of serious hypersensitivity reactions (e.g., anaphylaxis) to famotidine or other histamine-2 (H2) receptor antagonists. History of serious hypersensitivity reactions (e.g., anaphylaxis) to famotidine or other H 2 receptor antagonists.

Warnings and precautions

Central Nervous System (CNS) Adverse Reactions: Elderly patients and patients with renal impairment at increased risk; reduce the dosage. (2.2, 5.1, 8.5, 8.6) GI Malignancy: Absence of GI symptoms does not preclude the presence of gastric malignancy; evaluate prior to initiating therapy. Central Nervous System Adverse Reactions Central nervous system (CNS) adverse reactions, including confusion, delirium, hallucinations, disorientation, agitation, seizures, and lethargy, have been reported in elderly patients and patients with moderate and severe renal impairment treated with famotidine.

Pregnancy

Pregnancy Risk Summary Available data with H 2 -receptor antagonists, including famotidine, in pregnant women are insufficient to establish a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes.

Storage and supply

Famotidine for Oral Suspension USP is suppliled as follows: NDC Strength Quantity Description 72603-171-01 40 mg/5 mL 50 mL when reconstitued/ Bottle containing 400 mg famotidine White to off-white powder forming a white to off-whote homogenous suspension with characteristic odor on constitution, containing 40 mg of famotidine per 5mL.

Source: Famotidine (Famotidine) — US FDA prescribing information, 2023-09-07, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.