Real-world experience with once-daily gabapentin for the treatment of postherpetic neuralgia (PHN).

Objectives: To evaluate the safety and effectiveness of once-daily gastroretentive gabapentin (G-GR) for the treatment of post-herpetic neuralgia in real-world clinical practice. Materials and Methods: Patients aged 18 years and above were divided into 2 cohorts: patients aged 70 years and below and patients above 70 years. All patients were titrated to 1800mg GGR/d over 2 weeks and maintained at that dosage for 6 weeks, for 8 weeks total treatment. To reflect clinical practice, exclusion criteria were limited to those in the product label. Efficacy was assessed using a visual analog scale (VAS) and the Brief Pain Inventory. Patient/Clinician Global Impression of Change scales were completed at week 8. Adverse events (AEs) were assessed. Results: The efficacy population included 190 patients (110, 70 y and below; 80, above 70 y). The mean percent change in VAS score at week 8 from baseline was -21.3%/ -20.4% (70 y and below/above 70 y). The proportion of patients with a Z30% reduction in VAS score from baseline was 51.8%/55.0% (70 y and below/above 70 y) and was 42.7%/37.5% for a Z50% reduction. Brief Pain Inventory scores were all significantly reduced by week 8. On the Patient Global Impression of Change instrument, more patients aged 70 years and below reported feeling "much" or "very much" improved from baseline (59.0% vs. 40.3%). G-GR was generally well tolerated. Thirty-seven (18.8%) patients experienced AEs that led to discontinuation. No patients died and 5 (2.5%) patients experienced serious AEs. The most common G-GR-related AEs (70 y and below/ above 70 y) were dizziness (11.7%/16.3%) and somnolence (3.6%/8.1%). Discussion: In real-world clinical practice, G-GR seems to be an effective, well-tolerated treatment option for patients with post-herpetic neuralgia, regardless of age.