Valacyclovir. New indication: for genital herpes, simpler administration

Valacyclovir, the metabolic precursor of acyclovir, is now approved for treatment and prevention of genital Infection with herpes simplex viruses. The clinical file is bulky and methodologically sound. For treatment of a first episode of genital herpes, a large comparative trial has shown that valacyclovir (1 g twice a day) is as effective as acyclovir (200 mg five times a day) when given for 10 days. For treating recurrences, two trials show that valacyclovir is as effective as acyclovir (200 mg five times a day) with a treatment period of 5 days. A daily dose of 1 g of valacyclovir is as effective as 2 g daily. Valacyclovir can be administered once a day. For prevention among patients with frequent recurrences, the efficacy of valacyclovir (500 mg/d in a single dose) has been proven in a placebo-controlled trial lasting 4 months. In these trials, valacyclovir and acyclovir were both well tolerated, with no major differences between the two drugs.