Adenine Arabinoside Therapy of Herpes Zoster in the Immunosuppressed. NIAID Collaborative Antiviral Study

We evaluated adenine arabinoside treatment of herpes zoster in immunodeficient patients in a randomized, controlled crossover study. The two study groups had similar characteristics. In spite of rapid natural healing, those receiving adenine arabinoside over the first five days had accelerated clearance of virus from vesicles (P = 0.01), and cessation of new vesicle formation (P = 0.004), and a shorter time to total pustulation (P = 0.001). Factors modifying the response to therapy included age, underlying disease, and the duration of zoster prior to therapy. Clinical toxicity was minimal. Laboratory assessment of bone-marrow, liver and renal function showed insignificant alterations as a result of therapy. These studies show that adenine arabinoside is a drug with promise for therapy of systemic herpes zoster in immunocompromised patients. It is most efficacious when administered during the first six days of disease (P = 0.001) to those who have reticuloendothelial neoplasia (P = 0.001) and are less than 38 years of age (P = 0.001).