Comparison of the efficacy and safety of valaciclovir and acyclovir for the treatment of herpes zoster ophthalmicus.

OBJECTIVE: To compare the efficacy and safety of valaciclovir and acyclovir in immunocompetent patients with herpes zoster ophthalmicus.

DESIGN: A multicenter, randomized, double-masked study.

PARTICIPANTS: One hundred ten immunocompetent patients with herpes zoster ophthalmicus diagnosed within 72 hours of skin eruption were treated; 56 were allocated to the valaciclovir group and 54 to the acyclovir group.

METHODS: Patients randomized to the valaciclovir group received two 500-mg tablets of valaciclovir three times daily and one tablet of placebo twice daily. Patients in the acyclovir group received one 800-mg tablet of acyclovir five times daily and one tablet of placebo three times daily for 7 days.

MAIN OUTCOME MEASURES: Main outcome measures included the frequency, severity, and duration of ocular complications, patient reports of zoster-associated pain, and the outcome of skin lesions. Tolerance was also assessed on the incidence and types of adverse effects and changes in laboratory parameters. The analysis was mainly descriptive and performed on an intent-to-treat basis.

RESULTS: Ocular complications of herpes zoster ophthalmicus were similar in the valaciclovir and acyclovir treatment groups. The main complications were conjunctivitis (54% and 52%, respectively), superficial keratitis (39% and 48%, respectively for punctate keratitis; 11% in each group for dendritic keratitis), stromal keratitis (13% in each group), and uveitis (13% and 17%, respectively). The long-term outcomes of these ocular complications were favorable and similar in both treatment groups. Pain duration and severity and outcome of skin lesions were similar between groups. Most patients reported prodromal pain. After 1 month, 25% of patients in the valaciclovir group and 31% in the acyclovir group still reported pain. The percentage of patients experiencing postherpetic neuralgia decreased during follow-up. The tolerance to acyclovir and valaciclovir was comparable and considered good. The most frequent adverse events were vomiting and edema of the eyelids or face (3%-5%). Three serious adverse events not linked to the study drugs occurred.

CONCLUSIONS: Valaciclovir is as effective as acyclovir in preventing ocular complications of herpes zoster ophthalmicus, including conjunctivitis, superficial and stromal keratitis, and pain. Tolerability of the two drugs is similar, but the dosing schedule of valaciclovir is simpler.