Tramadol definition on wiki

 Tramadol hydrochloride (Ultram, Tramal others below) is a centrally acting opioid analgesic, used in treating moderate to severe pain. The drug has a wide range of applications, including treatment for restless leg syndrome and fibromyalgia. It was developed by the pharmaceutical company Grünenthal GmbH in the late 1970s.[1][2]

Tramadol possesses weak agonist actions at the μ-opioid receptor, releases serotonin, and inhibits the reuptake of norepinephrine.[3][4][5][6][7][8][9]

Tramadol is a synthetic analog of the phenanthrene alkaloid codeine and, as such, is an opioid and also a prodrug (codeine is metabolized to morphine, tramadol is converted to O-desmethyltramadol). Opioids are chemical compounds which act upon one or more of the human opiate receptors. The euphoria and respiratory depression are mainly caused by the μ1 and μ2 receptors; the addictive nature of the drug is due to these effects as well as its serotonergic/noradrenergic effects. 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.