Famotidine: Uses, Dosage, Side Effects & Brands | MedexInfo

Famotidine

Rx Only

GenericFamotidine

Therapeutic ClassH2 Receptor Antagonist

Common Dose20–40 mg once or twice daily

Max / 24h80 mg

PregnancyCategory B

Indications ▼

Gastroesophageal reflux disease (GERD)

Peptic ulcer disease (gastric and duodenal ulcers)

Zollinger-Ellison syndrome

Heartburn and acid-related dyspepsia

Mechanism & Pharmacokinetics ▼

Mechanism: Competitively inhibits histamine H2 receptors on gastric parietal cells, reducing gastric acid secretion.

Pharmacokinetics: Oral bioavailability ~40–45%; peak plasma concentration 1–3 hr; metabolized minimally in liver; excreted mostly unchanged in urine; half-life ~2.5–3 hr (prolonged in renal impairment).

Dosage & Administration ▼

Patient Category	Recommended Dose	Max / 24h
Adults (GERD / Ulcers)	20 mg once daily at bedtime or 20 mg twice daily	40 mg
Severe ulcers / Zollinger-Ellison	40 mg twice daily, titrate as needed	160 mg (divided doses)
Children (≥1 mo)	0.5–1 mg/kg/day divided into 1–2 doses	40 mg

Side Effects ▼

Common: Headache, dizziness, constipation, diarrhea

Occasional: Rash, fatigue, nausea

Rare: Arrhythmia, thrombocytopenia, hepatotoxicity

Contraindications ▼

Hypersensitivity to famotidine or other H2 blockers

Severe renal impairment without dose adjustment

Drug Interaction ▼

May reduce absorption of drugs requiring acidic gastric pH (e.g., ketoconazole, atazanavir)

Minimal CYP interactions; generally safe with most medications

Pregnancy & Lactation ▼

Use only if clearly needed (Category B)

Excreted in breast milk in small amounts; use with caution

Clinical / Research Summary ▼

GERD Relief: Reduces heartburn and acid reflux symptoms effectively.

Ulcer Healing: Promotes gastric and duodenal ulcer healing in clinical trials.

Zollinger-Ellison Syndrome: Controls hypersecretion of gastric acid when titrated appropriately.

Safety Profile: Well-tolerated; mild GI and CNS effects most common.

Current Research: Comparing efficacy vs PPIs in long-term management of acid-related disorders.

Storage & Handling ▼

Store at 20–25°C; protect from moisture and light

Keep out of reach of children

Patient Counseling Points ▼

How to take: Usually before meals or at bedtime; follow doctor instructions

Missed dose: Take as soon as remembered; do not double dose

Possible side effects: Mild headache, constipation, diarrhea

Monitor: Symptom relief and renal function if long-term use

Drug interactions: Inform provider about other medications

Lifestyle advice: Avoid alcohol, spicy foods, and NSAIDs for better symptom control

Pregnancy and safety: Safe if clearly indicated; consult physician

Brand Names (Bangladesh & Global) ▼

Bangladesh (Local Brands):

Famotin Gastrozine Famosid

Global / International Brands:

Pepcid Pepzan

Medical Disclaimer: This clinical summary is for informational purposes only. Always follow guidance from a qualified healthcare professional for dosage, interactions, and use.

Reference Hubs:

• Drug Class: H2 Receptor Antagonists • Conditions: GERD & Peptic Ulcers • Pathway: Gastric Acid Secretion Inhibition • Clinical Evidence & Trials