Failure of High Dose 5-Iodo-2′-Deoxyuridine in the Therapy of Herpes Simplex Virus Encephalitis

Abstract

Two placebo-controlled double-blind studies were initiated to evaluate the therapeutic efficacy of 5-iodo-2′-deoxyuridine (idoxuridine) in biopsy-proved cases of herpes simplex virus encephalitis. Twelve patients who on clinical grounds were thought to have herpes simplex virus encephalitis underwent brain biopsy; six of these patients were proved to have this disease, three were considered probable cases, and three were considered doubtful. The patients with proved or probable herpes simplex virus encephalitis were treated with parenteral idoxuridine (or placebo) at a dose of 100 mg per kilogram per day for five days. The occurrence of unacceptable myelosuppression and the failure of idoxuridine therapy to prevent death led to the premature termination of both studies. (N Engl J Med 292:599–603,1975)