Qutenza (Capsaicin) 8% Patch Onset and Duration of Response and Effects of Multiple Treatments in Neuropathic Pain Patients

Introduction: Qutenza (capsaicin) 8% patch is used to treat various neuropathic indications, including postherpetic neuralgia (PHN) and human immunodeficiency virus-associated neuropathy (HIV-AN). Objectives: We conducted a meta-analysis of Qutenza studies to describe clinical phenomena of effects of Qutenza treatment better, such as onset and duration of pain relief, and the need for retreatments. Methods: The meta-analyses combined individual patient data (1313 participants with PHN and 801 with HIV-AN) from 7 completed randomized, double-blind, controlled studies. Studies had similar designs, and all used the Qutenza patch (8% capsaicin) and a low-dose control patch (0.04% capsaicin). A 30% response was defined as a >= 30% decrease in mean pain intensity score during week 2 to end of follow-up; complete pain relief was defined as an average pain intensity <= 1 during week 2 to end of follow-up. Duration of response was calculated using the data from long-term studies as the time from onset of response to offset of response, retreatment, or end of follow-up (whichever occurred first). Results: Overall 44% of PHN and 41% of HIV-AN patients had a 30% response, and 11% and 7%, respectively, had complete pain relief 2 to 12 weeks after treatment with Qutenza. The mean (median) onset of response to Qutenza was 3.4 (1) days for PHN and 6.5 (4) days for HIV-AN (delayed due to an initial increase in discomfort). The mean (median) duration of response after 1 Qutenza treatment was 5 (3) months. Of the patients followed-up for 12 months, 40% PHN and 36% HIV-AN patients had a 30% response, and 9% and 10%, respectively, had complete pain relief from week 2 to end of follow-up. Conclusions: Qutenza is effective in a high proportion of patients. In patients who respond to Qutenza, analgesia starts within a few days of treatment and lasts on average 5 months.