Effect of study country on efficacy and adverse event profile of once-daily gabapentin extended-release (G-ER) for the treatment of postherpetic neuralgia (PHN)

Abstract

G-ER has been demonstrated to be efficacious and well tolerated for treatment of PHN in a placebo-controlled, Phase 3 study conducted in the USA, Russia and Argentina. We examined the efficacy and tolerability of once-daily G-ER (1800 mg) as a function of study country. Patients with PHN ≥6 months and average daily pain (ADP) score ≥4 were randomized to G-ER or placebo for 10 weeks. The primary endpoint was baseline observation carried forward (BOCF) change in ADP, and rates of adverse events were compared.