Cobratide injection vs pregabalin for moderate-to-severe acute herpes zoster neuralgia: A randomized, double-blind,...

Acute herpes zoster (HZ) neuralgia impairs quality of life and may progress to postherpetic neuralgia (PHN). Existing analgesics are often limited by adverse effects in older adults.

To evaluate Cobratide injection for moderate-to-severe acute HZ neuralgia and explore its potential effect on PHN incidence.

In this multicenter, randomized, double-blind, double-dummy, active-controlled exploratory trial, 80 patients aged 50-70 years were assigned 1:1 to intramuscular Cobratide injection or oral Pregabalin for 28 days. The primary endpoint was change in average Numeric Rating Scale (NRS) pain score from baseline to day 28. No formal power calculation was performed.

At day 28, least-squares mean NRS reductions were 6.00 with Cobratide injection and 5.63 with Pregabalin (between-group difference, 0.37; P = .186). At week 12, PHN occurred in 0/27 and 3/27 evaluable patients, respectively (P = .236). Treatment-emergent adverse events occurred in 35.9% and 51.2% of patients, respectively.

Exploratory design, small sample size, and lack of systematic collection of zoster vaccination history and rash-onset timing limited inference.

Cobratide injection showed a similar magnitude of pain reduction to Pregabalin, with a favorable tolerability signal. Larger adequately powered trials are needed.