The Effect of Remifentanil on Established Sunburn-induced Hyperalgesia in Human Volunteers

Treatment of chronic pain is a major clinical challenge since chronic pain is frequent and leads to deterioration of quality of life. An injury or wound can lead to long term changes in the nervous system that make the skin more sensitive at and near the injury; this is termed hyperalgesia and occurs through long term depotentiation (LTP), i.e., a change in the synaptic interaction between neurons. Opioids are the gold standard for the symptomatic therapy of moderate to severe pain. Now, in animal studies the investigators have discovered previously unrecognized effects of opioids. UV-B irradaition of the skin of the thigh is an established model of priamary and secondary hyperalgeisa in humans. The investigators want to test the influence of remifentanil, an ultra-short acting opioid, on hyperalgesia observed after UV-B irradiation in human volunteers in a double blind cross-over prospective active placebo controlled clinical trial.