Effect of cimetidine on digoxin disposition in peptic ulcer patients

Summary Cimetidine inhibits the renal tubular secretion of creatinine and digoxin is partly excreted by the same pathway. In order to investigate a possible interaction between the two drugs, a randomized cross-over acute study has been conducted. Six patients with duodenal ulcers were given a single dose of digoxin (Dig) 0.75 mg i.v. with and without oral cimetidine 1200 mg/day. Cimetidine significantly reduced creatinine clearance from 157 to 132 ml/min. There was no significant difference in inulin clearance, 99.2 vs 97.5 ml/min, Dig elimination half life 53.9 vs 56.9 h, apparent volume of distribution 11.3 vs 11.6 l/kg, systemic clearance 2.42 vs 2.35 ml/min/kg, renal clearance 1.48 vs 1.62 ml/min/kg or urinary excretion of digoxin 49.5 vs 51.6% of dose without or with cimetidine. These results suggest that cimetidine does not influence the disposition of digoxin.