The pharmacokinetics and safety profile of oral ganciclovir in combinationwith trimethoprim in HIV- and CMV-seropositive patients

Aims We investigated the pharmacokinetics and safety profile of oral gancic lovir coadministered with trimethoprim in HIV-and CMV-seropositive patients . Methods In an open-label, randomized, 3-way crossover study, 12 adult males received oral ganciclovir 1000 mg every 8h, oral trimethoprim 200 mg once daily, or both drugs concomitantly in a sequence of three 7-day treatment p eriods. Pharmacokinetic parameters were determined and adverse events recor ded for each treatment. Results The presence of trimethoprim significantly decreased CLr (12.9%, P= 0.0068) and increased t(1/2) (18.1%, P=0.0378) of ganciclovir. However, th ese changes are unlikely to be clinically meaningful. There were no statist ically significant changes in trimethoprim pharmacokinetic parameters in th e presence of ganciclovir, with the exception of a 12.7% increase in C-min. Ganciclovir was well tolerated when administered alone or in combination w ith trimethoprim. Conclusions There was no clinically significant pharmacokinetic interaction between oral ganciclovir and trimethoprim when coadministered.