Three cases of vidarabine encephalopathy

Abstract

We report here three patients with encephalopathy developed after administration of Ara–A. All patients were female, in age of 80s or older. Disturbance of consciousness (three patients) or tremor (two patients) occurred following to intravenous infusion of Ara–A for their severe herpes zoster. Cerebrospinal fluid examination revealed no abnormal finding other than mild pleocytosis. All patients showed diffuse slowing of EEG without any abnormality in brain MRI. The patients had several factors which may cause high plasma concentration of Ara–A ; i.e., old age, renal dysfunction in case 1 (eGFR 32.6 ml/min/1.73m²), emaciation in case 2 (BMI 15.9), and renal dysfunction (eGFR 7.4 ml/min/1.73m²) and use of xanthine metabolism inhibitor (allopurinol) in case 3. These factors should be screened thoroughly to prevent Ara–A encephalopathy. One patient who was able to undergo monitoring for plasma concentration of 9–β–d–arabinofuranosyl hypoxanthine (Ara–Hx) showed prolonged elevation of Ara–Hx, which might be useful in prevention of Ara–A encephalopathy.