Different dosages of valaciclovir for the treatment of herpes zoster in adults: A randomized clinical study.

Abstract

The dosages of valaciclovir used for herpes zoster treatment recommended by Chinese pharmaceutical companies can differ considerably from those reported in the literature. This randomized clinical study compares the efficacy and safety of different oral valaciclovir doses for the treatment of herpes zoster in adults. A total of 214 patients with herpes zoster were enrolled and randomized into two groups according to age: 98 patients in the 18-44-year group (younger patients) and 116 patients in the 45-74-year group (middle-aged and elderly patients). Patients in the two age groups were then prescribed different doses of valaciclovir. The high-dose group was administered 900mg of valaciclovir, three times daily for 10days, whereas the low-dose group was administered 300mg of valaciclovir, two times daily for 10days. The efficacy and side effects of these regimens were recorded on days 6, 11 and 30. In total, 207 (of 214 enrolled) patients completed the study. Of the seven patients who discontinued the study, five discontinued because their follow-up time was not fixed and two withdrew after moving to other cities. At the 11th day after treatment, the clinical effect of high-dose valaciclovir groups were significantly better than that of the low-dose valaciclovir groups in middle-aged and elderly patients (p<0.05). The difference in visual analog scale (VAS) pain scores between the two dose groups was statistically significant in middle-aged and elderly patients at the 6th day(p<0.05), whereas there was no difference in younger patients (p>0.05). The VAS scores were significantly lower in high-dose group than in low-dose group at day 11 in both groups of patients(p<0.05).There was no statistically significant difference in the time to skin scab improvement between the two different dose groups in younger patients (p>0.05). Among middle-aged and elderly patients, the incidence of postherpetic neuralgia (PHN) was significantly lower in the high-dose group than in the low-dose group (p<0.05). The difference in the incidence of adverse reactions between the high-dose and low-dose groups was not statistically significant (p>0.05). Overall, the main side effect was headache. The present study indicates that early treatment with high-dose valaciclovir can significantly reduce pain in patients, especially in elderly patients, in whom it can also reduce the incidence of PHN. In terms of safety, no significant difference was noted in the incidence of adverse reactions between high- and low-dose groups.