title: Valaciclovir: new indications. In genital herpes: simpler administration.
abstract: (1) Valaciclovir, the metabolic precursor of aciclovir, is now approved for the treatment and prevention of genital infection by herpes simplex viruses.  (2) The clinical file is bulky and methodologically sound.  (3) For treatment of a first episode of genital herpes, a large comparative trial has shown that valaciclovir (1 g twice a day) is as effective as aciclovir (200 mg 5 times a day) when given for 10 days.  (4) In treatment of recurrences, two trials show that valaciclovir is as effective as aciclovir (200 mg 5 times a day) with a treatment period of 5 days.  A daily dose of 1 g valaciclovir is as effective as 2 g daily.  Valaciclovir can be administered once a day.  (5) For prevention in patients with frequent recurrences, the efficacy of valaciclovir (500 mg/day in a single dose) has been proven in a placebo-controlled trial lasting 4 months.  (6) In these trials valaciclovir and aciclovir were both well tolerated, with no major differences between the two drugs.
mesh_terms: D000212:Acyclovir / Q000031:analogs & derivatives / Q000627:therapeutic use*; D000998:Antiviral Agents / Q000627:therapeutic use*; D004341:Drug Evaluation; D006558:Herpes Genitalis / Q000188:drug therapy* / Q000517:prevention & control; D006801:Humans; D055502:Secondary Prevention; D016896:Treatment Outcome
chemical_list: D000998:Antiviral Agents; D000212:Acyclovir