Buprenorphine for neuropathic pain--targeting hyperalgesia.

Opioids are well known to relieve severe, acute, and chronic nociceptive pain, but neuropathic pain shows a relatively poor response to opioids. Buprenorphine, a partial mu and ORL-1-receptor agonist, kappa-delta receptor antagonist, interacts with different G proteins than potent mu agonists and hence is not cross-tolerant to standard opioids. Buprenorphine blocks central sensitization (hyperalgesia) that is commonly found with neuropathic pain. We present a patient with neuropathic pain and tactile allodynia in which buprenorphine alleviated the hyperalgesia to a greater extent than pain severity. We found buprenorphine to be effective in reducing hypersensitivity in neuropathic pain when pure mu agonists fail to produce a response or in individuals who are intolerant to pure mu agonists.