Recurrent genital herpes suppressed by oral acyclovir: a multicentre double blind trial.

Eighty-eight of 111 patients with frequently recurring genital herpes attending five centres completed a randomized, double-blind, cross over trial with 200 mg oral acyclovir four times daily for 84 days before or after a similar course of placebo tablets. During the course of placebo 77 (88%) patients reported the development of lesions, four (5%) the development of symptoms and/or erythema but no further signs of a recurrence and seven (8%) remained entirely free of symptoms and signs. In contrast during acyclovir therapy only 11 (13%) patients reported lesions, a further 37 (42%) the development of symptoms and/or erythema only, while 40 (45%) patients remained entirely free of symptoms and signs. For each parameter the difference between active and placebo treatments was highly significant (P less than 0.001). Median times to recurrence after the end of both courses were similar. The drug was well tolerated and the findings indicate that continuous oral acyclovir therapy has a place in the management of frequent recurrences of genital herpes though the indications are not entirely clear. One possibility is the suppression of recurrence at times when it would be especially unwelcome such as during examinations or holidays.