Treatment of Herpes simplex virus infections with topical antiviral agents.

Clinical studies of topical therapy against Herpes simplex virus (HSV) infections have been reviewed. Idoxuridine (IDU) 15% in dimethyl sulfoxide (DMSO), interferons, and penciclovir result in significant clinical benefit against this virus. IDU reduced pain duration and decreased time to loss of crust in a study of 301 patients. Alpha-interferon has shown synergism with other anti-HSV drugs such as caffeine, trifluorothymidine (TFT), DMSO, and nonoxynol-9. Finally, in a study of over 2,000 patients, application of penciclovir cream, both early and late in the course of HSV infection, decreased the duration of lesions, pain, and viral shedding. Acyclovir (ACV)-resistant strains of HSV are susceptible to (S)-1-(3-hydroxy-2-phosphonylmethoxypropyl) cytosine (HPMPC), and ascorbic acid shows promising effects against HSV. Using a vehicle that enhances skin penetration of a drug or possibly further exploring combination therapy may result in efficacious treatment of HSV. The possibility of topical vaccination or topical gene therapy may also prove beneficial in the future.