controlled study of ngx-4010 for the treatment of postherpetic neuralgia

Conditions: Herpes Zoster; Neuralgia; Pain; Peripheral Nervous System Diseases

Summary: the purpose of the study is to assess the efficacy, safety and tolerability of ngx 4010 applied for 60 minutes for the treatment of phn.


Eligibility criteria:
inclusion criteria: * at least 18 years of age. * be in good health. * diagnosis of postherpetic neuralgia (phn) made by the primary treating physician or investigator, and at least 3 months post-vesicle crusting. * screening pain sum score of 12 to 36. * intact, unbroken skin over the painful area(s) to be treated. * if taking chronic pain medications, be on a stable (not prn) regimen for at least 21 days prior to treatment visit (day 0) and willing to maintain medications at same stable dose(s) and schedule throughout the study. * female subjects with child-bearing potential must have a negative serum beta hcg pregnancy test, to be performed at the screening visit. * all subjects must be willing to use effective methods of birth control and/or refrain from participating in a conception process during the study and for 30 days following experimental drug exposure. * be willing and able to comply with protocol requirements for the duration of study participation. (such requirements include, but are not limited to: completing a daily pain diary, attending all study visits, and refraining from elective surgery and extensive travel during study participation.) exclusion criteria: * concomitant opioid medication, unless orally or transdermally administered and not exceeding a total daily dose of morphine 60 mg/day, or equivalent. parenteral opioid use is excluded, regardless of dose. * unavailability of an effective rescue medication strategy for the subject, such as unwillingness to use opioid analgesics during treatment, or high tolerance to opioids precluding the ability to relieve treatment-associated discomfort with roxicodone®, as judged by the investigator. * active substance abuse or history of chronic substance abuse within the past year, or prior chronic substance abuse judged likely to recur during the study period by the investigator. * recent use (within 21 days preceding the treatment visit \[day 0\]) of any topically applied pain medication, such as non-steroidal anti-inflammatory drugs, menthol, methyl salicylate, local anesthetics (including lidoderm®), steroids or capsaicin products on the painful areas. * current use of any investigational agent, or class 1 anti-arrhythmic drugs (such as tocainide and mexiletine). * significant pain of an etiology other than phn, for example, compression-related neuropathies (e.g., spinal stenosis) or fibromyalgia or arthritis. subjects must not have significant ongoing pain from other cause(s) that may interfere with judging phn-related pain. * painful phn areas located only on the face, above the hairline of the scalp, and/or in proximity to mucous membranes. (investigational treatment with ngx-4010 is not allowed in these areas.) * any implanted medical device (spinal cord stimulator, intrathecal pump or peripheral nerve stimulator) for the treatment of neuropathic pain. * hypersensitivity to capsaicin (i.e., chili peppers or over-the-counter (otc) capsaicin products), local anesthetics, roxicodone® or adhesives. * significant ongoing or untreated abnormalities in cardiac, renal, hepatic, or pulmonary function that may interfere either with the ability to complete the study or the evaluation of adverse events.

Keywords: dermal assessment pain measurement diary analgesics/*therapeutic use capsaicin/*administration & dosage/adverse effects herpes zoster/*complication/drug therapy neuralgia/*drug therapy/etiology pain peripheral nervous system diseases/*complications