SummaryThis study was designed to compare the effects of equivalent therapeutic doses of two H2antagonists, cimetidine and ranitidine, on steady-state procainamide pharmacokinetics. Six healthy men were given 500 mg sustained-release procainamide every 6 h, for a total of 13 doses, on three occasions. Subjects were randomly assigned to three treatments by a Latin-square design: cimetidine 1,200 mg/day, ranitidine 300 mg/day, and no H2-receptor antagonist (control) for 4 days. Cimetidine significantly increased the procainamide area under the serum concentration-time curve by 43percnt;, decreased renal clearance by 36percnt;, and decreased the ratio of systemic clearance of procainamide to bioavailability by 28percnt;. Ranitidine did not significantly alter procainamide steady-state pharmacokinetics.
展开▼
