Objectives: Pain is an important driver of quality of life and health care resource use, though few treatments are available to effectively treat neuropathic pain. The purpose of this study was to characterise the retreatment interval, patch usage and clinical effectiveness of the capsaicin 8% patch 'Qutenza' (QTZ) when used to treat peripheral neuropathic pain in clinical practice. Methods: Interim data were available from a prospective, observational study of people with neuropathic pain treated with QTZ throughout Europe (n= 340); the ASCEND study. The Numeric Pain Rating Scale (NPRS) recorded pain on an integer scale between 0 (no pain) and 10 (worst imaginable pain). Time to retreatment was evaluated using the Kaplan-Meier method, accounting for right-censored observations. Change in pain severity was evaluated using independent sample and paired samples t-tests. Results: At baseline, the mean NPRS was 6.82 (SD 1.89). At eight weeks following first treatment, 43.8% of patients achieved a 30% reduction and 24.2% a 50% reduction. In this analysis, 105 (30.9%) patients were retreated with QTZ at least once, of which 26 (7.7%) had two re-treatments, and 5 (1.5%) had three or more re-treatments. There was no difference in baseline NPRS between those that progressed to receiving multiple treatments and those treated once (mean NPRS= 6.87 vs. 6.67 units respectively (p= 0.355)). Mean NPRS prior to the second application was 5.66 (2.09; p< 0.001), and 5.19 (2.38; p= 0.010) prior to subsequent applications. The mean number of patches used at the first, second and third applications was 1.18 (0.81), 1.16 (0.75), and 1.19 (1.07), respectively (p= 0.115, p= 0.214). The median time from first to second treatment was 22 weeks (95% CI 17-27), and from second to third a further 21 weeks (95% CI 16-26). Conclusions: This study shows that capsaicin 8% patch use and retreatment intervals are stable across successive treatments suggesting consistent efficacy.
Chambers, C., Poole, C., Berni, E., Odeyemi, I., Thomas, R., & Currie, C. (2014). Treatment Of Neuropathic Pain With The Capsaicin 8% Patch Qutenzatm: Evaluation Of Time To Retreatment, Patch Usage And Pain Alleviation. Value in Health, 17(3), A224. https://doi.org/10.1016/j.jval.2014.03.1309