Acyclovir: an update of the clinical applications of this antiherpes agent.

This paper reviews the clinical evaluation of acyclovir in the treatment of herpes-virus infections, predominantly those due to herpes simplex and varicella-zoster viruses. Intravenous, oral and topical acyclovir have been reported to be effective in the therapy of a wide variety of established herpes simplex virus infections and the systemic drug has been shown to be capable of suppressing reactivation of that virus. Although acyclovir has less activity against varicella-zoster virus, infections caused by this agent are also susceptible to intravenous and possibly oral therapy. Clinical efficacy against Epstein-Barr virus and cytomegalovirus infections has not been demonstrated but several studies are currently in progress. Limited evidence of in vivo activity against hepatitis B virus also requires further evaluation. Continued studies on tolerance of the drug in clinical use has confirmed the early promise of this selective antiviral, whilst initial concern about the development of widespread resistance has not been borne out in practice.