A randomized double-blind placebo controlled trial of oral acyclovir in renal allograft recipients

Fifty renal transplant patients were randomized to receive either 800 mg acyclovir by mouth four times daily or identical placebo tablets for prophylaxis of herpes simplex infection. Patients were followed weekly to assess reactivation of herpes simplex, varicella zoster virus, Epstein-Barr virus or cytomegalovirus (CMV) infections. The patients received standard immunosuppressive regimens including cyclosporine A. Acyclovir suppressed secretion of herpes simplex virus in treated patients (P=0.001). Three episodes of mucocutaneous herpes simplex virus occurred in placebo recipients and one in a noncompliant acyclovir recipient. A clinically important difference in graft survival was demonstrated, but because of sample size failed to reach statistical significance (P=0.11). No reactivation of varicella zoster virus, Epstein-Barr virus or CMV infection was detected in either group. Toxicity was limited to central nervous irritability. The authors conclude that high dose oral acyclovir provides effective prophylaxis for prevention of herpes simplex virus infections in renal transplantation and may be associated with increased graft survival, perhaps from suppression of CMV infection.