A double-blind, randomized study assessing the equivalence of valacyclovir1000 mg once daily versus 500 mg twice daily in the episodic treatment of recurrent genital herpes

Valaciclovir is a prodrug of acyclovir with more favourable bioavailability . Twice daily oral administration of valacyclovir is recommended in patient s with genital herpes. A double-blind, randomized, controlled, multicriteri a equivalence trial was conducted to determine whether od treatment with va lacyclovir 1000 mg is as effective as bd treatment with 500 mg in patients with recurrent genital herpes. A total of 922 immunocompetent outpatients w ere 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 ce ssation of pain, discomfort or itching, the percentage of abortive episodes and safety. Equivalence was assessed by comparison of 80% confidence limit s for each measure; the two regimens were regarded as equivalent if the low er confidence limit was higher than a pre-determined equivalence limit calc ulated to show a maximum 10% inferiority of valacyclovir 1000 mg od against valaciclovir 500 mg bd. Intention-to-treat analysis showed that the two tr eatments were equivalent for each outcome measure. Hence, it is concluded t hat valacyclovir 1000 mg od is as effective as 500 mg bd as self-initiated therapy in patients with recurrent genital herpes.