Famotidine Dosing Guidelines

Standard Maximum Dosing by Indication

• The American College of Cardiology recommends a maximum dose of 40 mg daily for stress ulcer prophylaxis in ICU patients 1

Special Clinical Contexts

• The standard premedication protocol is 20 mg IV or PO, providing acid suppression 2
• Perioperative use of 20 mg IM provides acid suppression for approximately 6 hours when oral/IV routes are unavailable 2
• For children weighing less than 40 kg, the maximum dose is 1 mg/kg/day divided into 2 doses 1

Pharmacokinetics and Pharmacodynamics

• Oral famotidine provides antisecretory activity for 10-12 hours, supporting twice-daily dosing for sustained acid suppression 2
• IM famotidine provides approximately 6 hours of acid suppression 2
• Tolerance to H2-receptor antagonist therapy develops within 6 weeks of continuous use, requiring periodic reassessment 2

Drug Interactions

• The American College of Cardiology states that famotidine does not interfere with clopidogrel antiplatelet activity, making it preferred over PPIs in patients on dual antiplatelet therapy 3, 4, 2, 5