Tramadol

Tramadol is a synthetic stripped-down piperidine-analog of the phenanthrene alkaloid codeine and, as such, is an opivoid and also a prodrug. Opioids are chemical compounds which proceed upon one or more of the human opiate receptors (the euphoria, addictive nature and respiratory depression are mainly caused by the Mu(µ) 1 and 2 receptor. The opioid agonistic effect of tramadol and its major metabolite(s) are almost completely 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.