title: Valacyclovir. New indication: for genital herpes, simpler administration.
abstract: 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.
mesh_terms: D000212:Acyclovir / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D006558:Herpes Genitalis / Q000188:drug therapy*; D006801:Humans; D012008:Recurrence; D000077483:Valacyclovir; D014633:Valine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D000998:Antiviral Agents; D014633:Valine; D000077483:Valacyclovir; D000212:Acyclovir