Objective: To determine the efficacy of high-dose oral acyclovir in preventing cytomegalovirus (CMV) and other herpesvirus disease in patients with advanced HIV disease and to evaluate its effect on patient survival.
Design: Double-blind, placebo-controlled randomized trial of up to 1 year's therapy.
Setting: Outpatient clinics in 16 hospitals in Europe and Australia.
Participants: A total of 302 patients with Centers for Disease Control and Prevention stage IV HIV disease, seropositive for CMV and with CD4+ lymphocyte counts < or = 150 x 10(6)/l.
Interventions: Oral acyclovir (800 mg, four times daily) or matching placebo for 48 weeks.
Main outcome measures: Time to development of CMV and other herpesvirus disease. Following the results of another study, the protocol was amended to make survival a second major endpoint.
Results: Acyclovir failed to reduce the incidence of CMV disease: the probability of developing CMV disease at 1 year was 0.24 and 0.23 in the placebo and acyclovir groups, respectively (P = 0.53). However, acyclovir significantly reduced the probability of dying at 1 year of follow-up (from 0.39 to 0.23; P = 0.018). As expected, acyclovir significantly reduced the incidence and frequency of herpes simplex virus disease. There were no notable differences between treatment groups in clinically adverse experiences and no changes in haematological parameters to indicate clinically significant drug-induced toxicity.
Conclusions: High-dose acyclovir failed to reduce the incidence of CMV disease, but significantly reduced the probability of dying at 1 year of follow-up.