A Case of Severe Ganciclovir-Induced Encephalopathy
A 55-year-old man started to receive hemodialysis because of diabetic renal failure 2 years previously. He underwent renal transplantation 1.5 years previously, and had been receiving immunosuppressants since then. Eight months after transplantation, the serum creatinine level increased to 4.4 mg/dl. He had CMV enteritis with occult blood in the stool and an elevated CMV pp65 (C7-HRP) antigen level in blood mononuclear cells. Intravenous ganciclovir (150 mg/day) was administered for 11 days, followed by valganciclovir (450 mg/day). Because the enteritis was very severe, ganciclovir and valganciclovir were not reduced to maintenance doses, which are generally half of starting doses. Two days after starting valganciclovir, he had unsteady gait, but could walk unaided. On the next day, the patient needed assistance with walking. His consciousness was mildly disturbed (E3, V5, and M6 on the Glasgow Coma Scale). One day later, he became delirious intermittently. Two days later, he was found on the floor after falling, without major injuries. He was suspected to be irritated and exhausted because of severe enteritis. Nine days after starting valganciclovir, his level of consciousness worsened (E3, V3, and M5), and he could not receive oral drugs, including valganciclovir. Neurologists were consulted. Encephalitis was unlikely, since no meningeal signs or fever was noted; the cell count was normal (0.33 cells/μl) in the CSF, and the protein concentration marginally elevated (54 mg/dl). CMV, herpes simplex virus, varicella-zoster virus, and Epstein-Barr virus DNA was later found to be negative in the CSF. Ganciclovir-induced encephalopathy was suspected, and the drug was withdrawn. Because of the risk of further falls, hemodialysis using a VPS-15HA membrane, a vitamin E-coated polysulfone membrane (Asahi Kasei Kuraray Medical, Japan) was performed twice in 2 days. His consciousness improved considerably after the first session of dialysis (E3, V4, and M6) and was completely restored on the next morning after the second session (E4, V5, and M6). The trough levels of ganciclovir in the serum and CSF were retrospectively measured and are shown in table .