A double-blind, randomized study assessing the equivalence of valacyclovir 1000 mg once daily versus 500 mg twice daily in the episodic treatment of recurrent genital herpes. Genival Study Group

Valaciclovir is a prodrug of acyclovir with more favourable bioavailability. Twice daily oral administration of valacyclovir is recommended in patients with genital herpes. A double-blind, randomized, controlled, multicriteria equivalence trial was conducted to determine whether od treatment with valacyclovir 1000 mg is as effective as bd treatment with 500 mg in patients with recurrent genital herpes. A total of 922 immunocompetent outpatients were treated with either regimen for 5 days; treatment was self-initiated at the first symptoms of the next recurrence. The principal outcome measures were the percentage of lesions healed at day 6, time to healing, time to cessation of pain, discomfort or itching, the percentage of abortive episodes and safety. Equivalence was assessed by comparison of 80% confidence limits for each measure; the two regimens were regarded as equivalent if the lower confidence limit was higher than a pre-determined equivalence limit calculated to show a maximum 10% inferiority of valacyclovir 1000 mg od against valaciclovir 500 mg bd. Intention-to-treat analysis showed that the two treatments were equivalent for each outcome measure. Hence, it is concluded that valacyclovir 1000 mg od is as effective as 500 mg bd. as self-initiated therapy in patients with recurrent genital herpes.