The efficacy of fentanyl TTS for the treatment of neuropathic pain remains to be established, although opioids in general are clearly effective for neuropathic pain and fentanyl TTS has been shown to be effective for treating other types of pain. We propose to measure functional outcomes, pain relief and side effects of fentanyl TTS for the treatment of neuropathic pain. Measures will be made at baseline and after titrating the drug to an effective level.

Inclusion Criteria:

• Age >18 years
• Neuropathic pain persisting for > 3 months
• Pain over the immediate previous three months
• The average of the least and usual pain intensity rating of 3 or greater (0-10 numerical rating scale) during the last week prior to enrollment

Exclusion Criteria:

• A history of substance abuse
• Allergic reaction to an opioid
• Significant pain of alternate etiology other than the neuropathic pain state
• Severe pulmonary disease
• Recent myocardial infarction (within the preceding three months)
• Pregnancy
• Dementia
• Encephalopathy
• Those with life expectancy of less than six months and HIV seropositivity.