Recent advances in antiviral therapy.

Virus replication is described, and the clinical trials and indications for amantadine, rimantadine, vidarabine, vidarabine phosphate, acyclovir, ribavirin, and other promising antiviral agents are reviewed. Amantadine and rimantadine are useful for the treatment and prophylaxis of viral influenza A infections. Vidarabine is a second-line agent and is effective for the treatment of herpes simplex encephalitis, neonatal herpes simplex types 1 and 2, and varicella-zoster infections. Vidarabine phosphate (also known as vidarabine monophosphate) has a similar spectrum of activity and can be administered in smaller volumes than vidarabine. Acyclovir has demonstrated clinical efficacy for chickenpox, shingles (herpes zoster), genital herpes, and other herpes simplex infections. Acyclovir is also useful for the suppression of herpes infections. Systemically administered ribavirin is indicated for the treatment of Lassa fever. Aerosol ribavirin is effective for the treatment of respiratory syncytial virus pneumonia in children and infants and influenza A infections in adults. Only acyclovir, amantadine, ribavirin, and vidarabine are used in clinical practice. Vidarabine phosphate and investigational agents such as rimantadine, ganciclovir (DHPG, BW B759U), phosphonoformate, and bromovinyl-deoxyuridine (BVDU) need further investigation.