Topical treatment of recurrent genital herpes simplex virus infections with trisodium phosphonoformate (foscarnet): double blind, placebo controlled, multicentre study.

A double blind, placebo controlled trial was performed in nine sexually transmitted diseases (STD) clinics in the United Kingdom and the Netherlands to investigate the efficacy of trisodium phosphonoformate (foscarnet) cream in treating recurrent genital herpes simplex virus (HSV) infection. The study group comprised 145 male and 85 female patients. Men received 0.3% foscarnet cream and women 1% foscarnet cream for five days. The difference in time to healing between patients receiving foscarnet or placebo was not significant. Fewer patients treated with foscarnet had positive viral cultures after treatment, but the difference was not significant. The development of new lesions, however, was significantly less common in patients given foscarnet. Though topical foscarnet is a safe drug, no appreciable efficacy in treating recurrent genital HSV infection could be shown.