Comparison of Efficacy, Tolerability and Adverse effect Profile of Acyclovir, Valacyclovir and Famciclovir in the Management of Herpes Zoster

Acyclovir, has been the predominant oral antiviral agent for the treatment of acute herpes zoster for past many years, especially in the government supply. Limited oral bioavailability of acyclovir requires frequent dosing, one of the reasons that makes it non-patient friendly. This study aimed to assess the efficacy, tolerability and adverse drug reactions of the other drugs valacyclovir and famciclovir used in treatment of Herpes Zoster and to compare their effectiveness with acyclovir, in preventing post herpetic neuralgia. 90 patients with herpes zoster presenting within 72hours of the onset of rash were enrolled and randomized into three groups of 30 each and were assigned acyclovir, valacyclovir and famciclovir respectively. The treatments were given for 7 days. Patients were periodically followed up till day 29 to assess the effect of the drugs. A statistically significant reduction of skin lesion and zoster associated pain were noticed in valacyclovir group day 22(P=0.013) and day 29(P=0.0004). A significantly greater proportion of patients in Valacyclovir group did not have Zoster associated pain at day 29(P=0.003). All the three drugs showed significant reduction in pain scores within the group between 2 consecutive visits. The reduction of pain was best with Valacyclovir followed by Famciclovir and least in Acyclovir. Other than resolution of pain which is faster with Valacyclovir compared to Acyclovir and Famciclovir, there is no difference in outcome of rash healing, abnormal sensation and adverse effect with three drugs. The results of the present study show that administration of Valacyclovir is a much more effective alternative in the treatment of Acute Herpes Zoster compared to acyclovir and famciclovir