We report a 52-year-old male undergoing CAPD who developed varicella-zoster virus (VZV) encephalitis. Because of the preceding herpes zoster, the patient was given acyclovir (ACV) per os, and thereafter disturbances of the central nervous system emerged. Thus, we had to distinguish between ACV encephalopathy and VZV encephalitis. However, based on the findings of Auditory-brainstem-response and lumbar puncture, we strongly suspected it as VZV encephalitis. Thus, intravenous ACV therapy was initiated again. One week later, the diagnosis of VZV encephalitis was confirmed by the evidence of rising anti VZV-IgG antibody titer in the cerebrospinal fluid. Two months later, the patient recovered completely from VZV encephalitis without any complications. There seem to have been no reports of VZV encephalitis in CAPD patients.
To clarify the pharmacokinetics of ACV in CAPD, 5mg/kg of ACV was intravenously administered to this patient and the blood concentration of ACV was serially measured. This dose was considered too high for the CAPD patient. Thus, daily administration of 2.5mg/kg or alternative day administration of 5.0mg/kg was thought to be effective and safe for CAPD patients with VZV infection.