Progressive Improvements with Repeated High-Concentration Capsaicin Patch: Real-World Data from the Retrospective CASPAR German Pain e-Registry Study in Postherpetic Neuralgia.

INTRODUCTION

Postherpetic neuralgia (PHN) is a chronic neuropathic pain condition that disproportionally affects older adults. First-line oral treatments often yield suboptimal relief and may cause systemic side effects and drug-drug interactions. Effective topical treatments offer the potential to address this significant unmet medical need in PHN. This CASPAR analysis evaluated real-world effectiveness and safety of the high-concentration capsaicin patch (HCCP) in patients with PHN.

METHODS

Real-world data were evaluated for a large PHN cohort extracted from the German Pain e-Registry as part of the retrospective, noninterventional, multicohort CASPAR study. Patients received one to four HCCP treatments over 12 months. Patient-reported outcomes included average pain intensity (API), quality of life (QoL), sleep impairment, mood, concurrent pain medications, and safety.

RESULTS

This analysis included 961 patients with PHN (mean age: 63.8 years, female: 69.7%; mean pain duration: 3.3 years) receiving one (n = 187), two (n = 209), three (n = 207), or four HCCP treatments (n = 358). Mean 24-h API decreased from 61.8 at baseline to 46.8 by month 3 (P < 0.001), and to 31.8 at month 12 (P < 0.001). Patients receiving four treatments had the greatest API reductions (63.7 at baseline versus 19.6 at month 12; P < 0.001), whereas improvements were lost in those who discontinued treatment. While ≥ 30% API response rates were similar across treatment groups at month 3 (25.6-30.7% of patients), those receiving additional treatments showed continued improvement, peaking at 99.7% by month 12 after four HCCP treatments. Trends were similar for other patient-reported outcomes, including QoL, sleep, and mood. Concomitant pain medication use decreased over time. Most adverse drug reactions were mild and application site-specific.

CONCLUSIONS

HCCP is an effective and well-tolerated topical treatment for patients with PHN, including older adults. After one treatment, improvements were noted in API, QoL, sleep, and mood outcomes, alongside decreased concomitant pain medication use, with progressive improvements following additional treatments. A Graphical Abstract is available for this article.