Famciclovir vs. aciclovir in immunocompetent patients with recurrent genital herpes infections: a parallel-groups, randomized, double-blind clinical trial

Background Twice-daily therapy with famciclovir (FCV) was shown to be effec tive for episodic therapy for recurrent genital herpes in a large placebo-c ontrolled trial. However, no study has been published to date comparing FCV and aciclovir (ACV). Objectives We have evaluated the effectiveness of FCV vs. ACV in the treatm ent of recurrent genital herpes infection. Methods A multicentre, double-blind, double-placebo, randomized, parallel-d esign study, assessed for equivalence, was conducted. As the analysis was b ased on confidence intervals, a difference of lesion healing time between A CV and FCV (Delta) of 1.05 days with a standard deviation of 2.30 days was chosen. Two hundred and four outpatients were included. Patients self-initi ated oral therapy with 125 mg of FCV twice daily or ACV 200 mg five times d aily for 5 days. The principal end-point of the study was the complete heal ing of lesions. Duration of the complete resolution of all symptoms, and sa fety were also considered. Results The mean healing time was 5.1 days and 5.4 days for ECV and ACV, re spectively with a crude value of Delta = 0.25 days (CI 95%: -0.32; 0.82) in the intent-to-treat population. Therefore, the confidence interval for the difference between the two treatments lies entirely within the equivalence range (-1.05-1.05). The value of Delta in the per-protocol population [0.3 5 day (CI 95%: -0.24; 0.93)] was comparable between the two groups. No diff erences were detected in the proportion of patients having complete healing at the different days of evaluation as well as in the duration until the c omplete resolution of all the symptoms. The frequency, nature and severity of adverse events did not differ among the two treatment groups. Conclusions Twice-daily FCV was as effective and safe in the treatment of r ecurrent genital herpes simplex virus infection as five times daily ACV.