Acyclovir Treatment of the Chronic Fatigue Syndrome

Abstract

Twenty-seven adults with a diagnosis of the chronic fatigue syndrome were enrolled in a double-blind, placebo-controlled study of acyclovir therapy. The patients had had debilitating fatigue for an average of 6.8 years, accompanied by persisting antibodies to Epstein–Barr virus early antigens (titers ≥1:40) or undetectable levels of antibodies to Epstein–Barr virus nuclear antigens (titers <1:2) or both. Each course of treatment consisted of intravenous placebo or acyclovir (500 mg per square meter of body-surface area) administered every eight hours for seven days. The same drug was then given orally for 30 days (acyclovir, 800 mg four times daily). There were six-week observation periods before, between, and after the treatments.