Tramadol detection in sports.

Tramadol is a centrally acting synthetic opioid analgesic used similarly to codeine, to treat moderate to moderately severe pain. The drug has a wide range of applications, including treatment for Rheumatoid arthritis, restless legs syndrome and fibromyalgia. Tramadol possesses weak agonist actions at the μ-opioid receptor, releases serotonin, and inhibits the reuptake of norepinephrine. Opioids are chemical compounds which act upon one or more of the human opiate receptors. The opioid agonistic effect of tramadol and its major metabolite(s) are almost exclusively mediated by the substance's action at the μ-opioid receptor. This characteristic distinguishes tramadol from many other substances (including morphine) of the opioid drug class, which generally do not possess tramadol's degree of subtype selectivity.