Comparison of the Efficacy of Valacyclovir vs Acyclovir for the Prevention of Recurrent Herpes Simplex Virus Eye Disease

Purpose: To compare the efficacy of 1–year treatment with valacyclovir versus acyclovir in preventing recurrences of herpes simplex virus (HSV) eye disease. Methods: A prospective randomized study. Fifty two immunocompetent patients with a history of recurrent ocular HSV disease were included in the study. Twenty five were assigned to the valacyclovir group and 27 to the acyclovir group. Patients randomized to the valacyclovir group received one 500mg tablet daily and patients randomized to the acyclovir group received one 400mg tablet twice daily. Patients received oral treatment for 1 year. Eligible patients were older than 18 years of age, and had an episode of ocular HSV disease in the preceding 12 months but their disease had been inactive and untreated during 1 month before the beginning of the study. The study outcome was the rate of recurrences of ocular HSV disease during 12 month of treatment. Recurrences were classified as infections of the ocular surface (blepharitis, conjuncitivitis or epithelial keratitis), stromal keratitis (corneal infiltrate or corneal edema), or iritis. Results: The recurrence rate of any type of ocular HSV disease during the 12–months treatment period was 24.0% in the valacyclovir group compared to the 22.2% in the acyclovir group (p>0.05). There was no clinically significant difference in the nature, frequency or severity of adverse events between the two groups. The most frequent adverse events were nausea and headache. No serious complications occurred in both groups. Conclusions: In this study 1–year suppression therapy with oral valacyclovir (500 mg tablet daily) has shown to be effective and well tolerated as acyclovir (400 mg tablet twice daily) to reduce the rate of recurrent ocular HSV. Potential benefits of the once daily regimen of valacyclovir include improved patient compliance.