A comparative study to evaluate the efficacy and safety of acyclovir and famciclovir in the management of herpes zoster.

Background: Over the years, acyclovir has been the oral antiviral agent approved for the treatment of patients with acute herpes zoster,Its effectiveness in lessening the acute signs and symptoms of herpes zoster has been established but the effects on post herpetic neuralgia are less clear cut. Famciclovir is a new member of guanine nucleoside family of drugs. It is a well absorbed oral form of penciclovir with longer half life. This was a open comparative randomized study carried out to compare the safety and efficacy of famciclovir administered at 250mg thrice daily with acyclovir 800mg five times daily for the treatment of acute uncomplicated herpes zoster in immunocompetent individuals aged above 40 years.

Aim: To assess the clinical profile of Herpes zoster, compare the efficacy and safety of acyclovir and famciclovir in the treatment of herpes zoster and to describe the effectiveness of acyclovir and famciclovir preventing post herpetic neuralgia.

Methods: A total of 100 newly zoster were randomized in 1:1 ratio into acyclovir and famciclovir groups after inclusion criteria were satisfied.Treatment was initiated within 72 hrs of onset of symptoms and was continued for 7 days and evaluated at the end of each week up to six weeks period for full crusting of the lesions, complete healing of the lesion and loss of acute pain.

Results: It was observed that famciclovir was as effective as acyclovir with no significant difference in time taken for full crusting, complete healing of lesions or loss of acute pain. Famciclovir was well tolerated with a better safety profile comparable to that of acyclovir. Constipation, headache, nausea and vomiting were the most commonly reported adverse effects, but constipation was considered to have a possible relationship to treatment.

Conclusion: In conclusion, oral famciclovir administered three times daily for 7 days during acute zoster infection is as effective as acyclovir, administered 800mg five times daily.In addition it offers significant benefit by providing a well tolerated, cost effective, convenient dosage regime and accelerated rate of lesion resolution and a reduced duration of PHN.