Capsaicin 8% Dermal Patch for Neuropathic Pain in a Pain Unit.

ABSTRACT

AIMS: Pain units manage approximately 20% of the patients with neuropathic pain, usually presenting with severe uncontrolled pain associated with substantial impairment of quality-of-life and disability. We aimed to analyze the experience with the capsaicin 8% dermal patch for managing patients with neuropathic pain in a pain unit. DESIGN: This was a post-authorization observational and retrospective study conducted at a single pain unit on patients with peripheral neuropathic pain under routine clinical care. METHODS: Diagnosis of neuropathic pain was based on the Douleur Neuropathique 4 (DN4) questionnaire. Evaluations included pain intensity according to a visual analog scale and the quality-of-life as evaluated with the European Quality of Life-5 Dimensions (EQ-5D). RESULTS: We included 66 patients with neuropathic pain lasting for a median of 24 months. The most frequent diagnosis was iatrogenic neuropathic pain (47%) and two thirds of patients exhibited extreme pain or discomfort. Pain intensity was reduced significantly from a mean (standard deviation [SD]) of 7.20 (1.95) at baseline to 6.02 (2.77) at month 3, leading to a mean change from baseline of 1.19 (95% confidence interval [CI], 0.59 to 1.78; p < .001; Cohen's d 0.49). The extent of the pain area was also significantly reduced from a median (interquartile range [IQR]) of 169.5 cm2 (69.3-299.9) at baseline to 121.2 cm2 (35.4-183.9) at month 3 (p < .001). There was an improvement in most dimensions of quality-of-life, especially regarding "usual activities," "pain/discomfort," and "anxiety/depression." Tolerability was consistent with the known profile. CONCLUSIONS: Our results suggest that the capsaicin 8% dermal patch is a useful and well-tolerated treatment option for managing peripheral neuropathic pain in pain units.