Neurotoxicity of valacyclovir in peritoneal dialysis: A pharmacokinetic study

Valacyclovir is an effective oral agent for the treatment of herpes virus i nfection, however, the pharmacokinetics of the drug are altered in renal fa ilure. It is increasingly recognized that dose adjustment of oral valacyclo vir in renal failure is necessary to avoid neurotoxicity. We studied this d rug in a continuous ambulatory peritoneal dialysis (CAPD) and immunocomprom ised patient. She developed neurotoxicity with an adjustment dosage of vala cyclovir for a cutaneous tester infection. The elimination half-time (15 h) was similar to that reported for end-stage renal disease patients, while t he steady-state volume of distribution (85 l) and the area under the curve concentration (127 mg/l.h) were greater. The mean CAPD dialysance was only 5.27 ml/min with less than 1% of an administered dose being recovered in th e 24-hour dialysate. 48 h after interrupting treatment, she recovered norma l neurological status and 500 mg of valacyclovir every 2 days was effective and well tolerated. Copyright (C) 2001 S. KargerAG, Basel.