Mefloquine pharmacokinetics in healthy subjects and in peptic ulcer patients after cimetidine administration

The pharmacokinetics of orally administered mefloquine were determined in six healthy male subjects and in six ulcer patients before and after a 3-day course of cimetidine (400 mg morning and evening). Peak plasma concentrations C-max and AUC(0-infinity) were similarly and significantly (P <0.05) increased after cimetidine pretreatement in both healthy subjects and peptic ulcer patients C-max was increased by 42.4% and 20.5 % while AUC(0-infinity) was increased by 37.5% in healthy and peptic ulcer subjects respectively. The values of t(1/2ab) absorption and t(1/2 beta) elimination, totall crearance CLT/F and volume of distribution were altered to varying levels after cimetidine treatment but the changes were not statistically significant in both healthy and peptic ulcer subjects. The established long t(1/2 beta) and this apparent interaction between mefloquine and cimetidine which resulted in increased mefloquine plasma concentration might be of clinical significant in patients with neurological/psychiatric history.