Visceral herpesvirus infections in leukemic patients receiving cytarabine

Autopsy evidence of herpesvirus infection was found in visceral organs of four leukemic patients who had received large doses of cytarabine (cytosine arabinoside; Ara-C) shortly before their death. In three of these patients the infection was clinically unsuspected; in the fourth, cutaneous herpes zoster developed after administration of 300 mg of cytarabine daily for the preceding five days. Although cytarabine exhibits pronounced in vitro virucidal activity against herpes viruses and has been successfully used in clinical treatment of severe herpesvirus infections, the present findings and a review of the recent literature cast doubt on the antiviral effectiveness of this drug, particularly in already immunosuppressed patients, and suggest instead that such patients actually have an increased risk for development of disseminated herpesvirus infection owing to further depression of host defenses by the drug.