Advances in antiviral therapy

Recent developments have increased the options for treatment of viral infections. Vidarabine, an agent originally released for herpes simplex encephalitis, has more recently been shown to be of benefit in neonatal herpes simplex infection and in varicella-zoster infections in immunocompromised hosts. The introduction of acyclovir represents a major advance in antiviral therapy because of its low host toxicity and marked selectivity for herpes simplex and varicella-zoster viruses. Extensive controlled clinical trials demonstrate efficacy in the treatment of infections caused by these viruses in the immunocompromised host and in genital herpes simplex infections in normal hosts. The use of recombinant DNA technology has increased the purity, variety, and availability of interferons for clinical trial. Earlier experience with natural buffy coat-derived alpha interferon showed efficacy in the treatment of varicella-zoster infections in the immunocompromised host, as well as prophylaxis of herpes virus infections in high-risk populations. These results have to be confirmed using the newer interferon preparations. Under development are a variety of new drugs with broadened viral spectrum and improved pharmacokinetic properties. These include nucleoside analogues and novel interferons with modified amino acid sequences. One or more of these agents, used singly or in combination, may prove useful in the more difficult therapeutic problems, such as cytomegalovirus and hepatitis B infections.