As per the findings of a retrospective observational study, amenamevir (AMNV) could lower acute herpes zoster (HZ) pain more efficiently than famciclovir (FCV). Yukako Kageshima et al. aimed to explore the impact of AMNV and FCV on pain intensities of acute HZ and the occurrence of postherpetic neuralgia (PHN).

A total of 143 AMNV-treated and 131 FCV-treated adult patients with HZ were recruited. The pain scores of both groups were evaluated with the aid of 11-point numerical rating scale (NRS). NRS pain scores were compared between the study groups using the Mann-Whitney U test while the occurrence of PHN was statistically evaluated using Pearson’s chi-square test. For identifying predictors of PHN, the univariate logistic regression analysis was utilized.

Compared to FCV-treated subjects, the pain scores during the acute HZ period remained substantially reduced in AMNV-treated subjects. However, the pain score at day 0 prior to the intervention didn’t vary between them. Furthermore, the occurrence of PHN did not vary between the groups (9.8 % vs. 11.5 %). The pain score at weeks 2-3 in the total cohort was substantially related to PHN development (r2 = 0.180).

AMNV could lower the acute HZ pain more efficiently than FCV in late visitors getting the treatment post 3 days after commencement, but not in early visitors getting the treatment within 3 days. Hence, AMNV has superior efficacy compared to FCV for the management of acute HZ pain. AMNV didn’t minimize PHN occurrence possibly due to the multifactorial etiology of PHN, concluded the study authors.