title: An open-label pilot study of high-concentration capsaicin patch in painful HIV neuropathy.
abstract: Peripheral neuropathy is the most frequent neurological complication of human immunodeficiency virus (HIV)-1 infection and is commonly associated with the development of chronic pain. This open-label, 12-week pilot study assessed the efficacy, tolerability, and safety of a high-concentration capsaicin dermal patch (NGX-4010; capsaicin, 640microg/cm2, 8% w/w) to treat painful HIV-associated distal sensory polyneuropathy (DSP). Eligible patients had moderate-to-severe pain in both feet due to HIV-associated DSP or antiretroviral toxic neuropathy. Patients received a single 60-minute application of the investigational high-concentration capsaicin patch to the affected areas. The primary outcome measure was the mean percent change in numeric pain rating scale (NPRS) during weeks two to 12 postadministration. After a single 60-minute NGX-4010 application, the mean percent change from baseline in "average pain for past 24 hours" NPRS scores during weeks two to 12 was -40% (95% CI: -61%, -19%; P=0.0020). Similar results were observed for "worst pain for past 24 hours" and "pain now" scores. Eight of 12 patients (67%) were treatment responders (> or =30% pain decrease). Four of 12 patients (33%) experienced a > or =50% reduction in pain. Treatment was generally well tolerated. Treatment-associated pain was self-limited and could be managed with short-acting opioids. This study demonstrates that treatment of painful HIV-associated neuropathy with a single application of NGX-4010, a high-concentration capsaicin patch, was feasible, well tolerated, and associated with significant reduction in pain over the 12 weeks studied. No safety concerns were identified. Controlled studies of NGX-4010 for the treatment of painful HIV-associated neuropathy are warranted.
authors.affiliation: Mount Sinai School of Medicine, New York, NY 10029, USA. david.simpson@mssm.edu
authors.forename: David M
authors.initials: DM
authors.lastname: Simpson
authors.forename: Lydia
authors.initials: L
authors.lastname: Estanislao
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Brown
authors.forename: James
authors.initials: J
authors.lastname: Sampson
mesh_terms: D000287:Administration, Topical; D000328:Adult; D002211:Capsaicin / Q000008:administration & dosage* / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy*; D010865:Pilot Projects; D011115:Polyneuropathies / Q000188:drug therapy*; D018689:Sensory System Agents / Q000008:administration & dosage* / Q000009:adverse effects; D016896:Treatment Outcome
chemical_list: D018689:Sensory System Agents; D002211:Capsaicin