Long-term safety of NGX-4010, a high-concentration capsaicin patch, in patients with peripheral neuropathic pain.
BACKGROUND
Postherpetic neuralgia (PHN) and painful human immunodeficiency virus-associated distal sensory polyneuropathy (HIV-DSP) are peripheral neuropathic pain syndromes that are difficult to treat. Current treatment options are often limited by poor tolerability.


OBJECTIVE
The objective of the current open-label study was to assess the safety of repeated applications of NGX-4010, a high-concentration capsaicin patch (capsaicin 8%), over one year, in patients with moderate to severe PHN or HIV-DSP.


METHODS
Patients had successfully completed a previous NGX-4010 study and had a pain level appropriate for further treatment. Eligible patients had not been treated with NGX-4010 within 12 weeks of study initiation. Patients received pretreatment with a topical local anesthetic (lidocaine 4%) for 60 minutes followed by either a 60-minute (PHN and HIV-DSP patients) or a 90-minute (HIV-DSP patients) treatment with NGX-4010. Patients could receive up to three additional treatments at intervals of > or = 12 weeks. Regardless of the number of treatments received, all patients were followed up for 48 weeks except for those withdrawing early.


RESULTS
A total of 106 patients were enrolled and received a total of 293 NGX-4010 treatments. The most frequently reported treatment-emergent adverse events were transient, mild-to-moderate application site erythema, pain, edema, and papules. Small, transient pain-related increases in blood pressure during and immediately after NGX-4010 application were observed. There was no evidence of an increased incidence of adverse events, dermal irritation, intolerability, or impaired neurological function with repeated treatments.


CONCLUSIONS
It is concluded that repeated treatments with NGX-4010 administered over a one-year period are generally safe and well tolerated.
Department of Neurology, Mount Sinai School of Medicine, New York, New York 10029, USA. david.simpson@mssm.edu
David M
DM
Simpson
Suzanne
S
Gazda
Stephen
S
Brown
Lynn R
LR
Webster
Shiao-Ping
SP
Lu
Jeffrey K
JK
Tobias
Geertrui F
GF
Vanhove
D000279:Administration, Cutaneous; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002211:Capsaicin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D015658:HIV Infections / Q000150:complications; D006801:Humans; D008297:Male; D008875:Middle Aged; D051474:Neuralgia, Postherpetic / Q000188:drug therapy; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D010523:Peripheral Nervous System Diseases / Q000188:drug therapy* / Q000209:etiology; D016896:Treatment Outcome; D055815:Young Adult
D002211:Capsaicin