Abstract
Valacyclovir (VACV) is a prodrug of acyclovir and well known as an effective medicine for the treatment of herpes zoster, however, acyclovir neurotoxicity rarely appears as a side-effect. We wish to report on two cases of neurotoxicity caused by oral VACV administration which they have dealt with, together with several bibliographical comments. Case 1: A 78-year-old female patient, without renal failure, was prescribed VACV at a dose of 3000mg per day. Five days later, disturbance of consciousness appeared, and she came to our hospital the next day. Acyclovir neurotoxicity and acute renal failure were suspected, because disturbance of consciousness and renal failure completely improved within several days after discontinuation of VACV administration. Case 2: A 73-year-old male patient, on hemodialysis third a week, was prescribed VACV at a dose of 3000mg per day. Two days later, psychiatric disorder appeared and he came to our hospital by ambulance. Acyclovir neurotoxicity due to overdosage was suspected. Administration of VACV was discontinued and hemodialysis was performed. A few days later, the symptoms were completely disappeared. It is important to remind acyclovir neurotoxicity when patient has disturbance of consciousness or psychiatric disorder following administration of VACV.
