[Transdermal buprenorphine: a current overview of pharmacological and clinical data]

Our understanding of the pathophysiologic mechanisms of chronic pain progresses; the complexity of the problem justifies our need for new molecules and new ways of administration that will help to further optimise and better individualize our pharmacologic therapies. Whereas acute pain can be considered an alarm signal, chronic pain constitutes, per se, a syndrome that requires a meticulous selection of the analgesic drug(s). Since pain is permanent, the continuous administration of the analgesic is recommended rather than an on demand administration. Transdermic modes of administration are of value for the treatment of chronic pain because they allow a progressive delivery of the active compound together with the maintenance of stable plasma levels of the drug. Buprenorphine is a semi-synthetic opioid that is available in the sublingual, injectable, or transdermic forms. The matrix patch of buprenorphine represents a major asset for the treatment of chronic pain, whether it be cancerous in origin, or not. Its efficacy and safety have been clearly demonstrated in randomised double blind trials as well as in post-marketing surveillance observations. Buprenorphine, administered as a transdermal therapeutic system, induces a dose-related pain relief, whatever the nature of the pain and the age of the patient. Buprenorphine also exerts an analgesic action on neuropathic pain. It differs from other opioids by its affinity as a partial agonist on mu and kappa receptors, and as a complete agonist of ORL-1 receptors. Therefore, transdermal buprenorphine will be useful to all physicians having to control severe pain by powerful opioids.