Substantial impairment of voriconazole clearance by high-dose meropenem in a patient with renal failure

Abstract

A critically ill patient with multiple postoperative infections repeatedly required profound voriconazole dose reductions whenever high-dose meropenem was added. Subsequent in vitro assessment confirmed inhibition of cytochrome P450 (CYP) 2C19 and CYP3A4 by meropenem, suggesting that during meropenem treatment, narrow therapeutic index drugs metabolized by these CYPs require close monitoring.