Cimetidine

Category: pharmacological

Aliases: Tagamet

Pharmacological Mechanism

H2 receptor antagonist — first H2 blocker to market; suppresses gastric acid via H2 → cAMP → parietal cell. Inhibits CYP1A2, CYP2D6, CYP3A4, CYP2C9 — substantially raises levels of theophylline, warfarin, phenytoin, propranolol. Largely supplanted by famotidine (no CYP DDI).

Half-Life (t½)

PO: 2h, IV: 2h

Dosing Guidelines

Target Organ Systems

Interactions