Tramadol hydrochloride (trademarked as Conzip, Ryzolt, Ultracet,
Ultram in the USA,Ralivia and Zytram XL in Canada) is a centrally acting
synthetic analgesic used to treat moderate to moderately-severe pain.
The drug has a wide range of applications, including treatment of
rheumatoid arthritis, restless legs syndrome and fibromyalgia. It was
launched and marketed as Tramal by the German pharmaceutical company Grünenthal GmbH in 1977.
Tramadol is a very weak μ-opioid receptor agonist, induces serotonin release, and inhibits the reuptake of norepinephrine. Tramadol is converted to O-desmethyltramadol, a significantly more potent μ-opioid agonist. The opioid agonistic effect of tramadol and its major metabolite(s) is almost exclusively mediated by such μ-opioid receptors. This further distinguishes tramadol from opioids in general (including morphine), which do not possess tramadol's degree of receptor subtype selectivity and which are much stronger opiate-receptor agonists. Similarly, the habituating properties of tramadol (such as they are) are arguably mainly due to μ-opioid agonism with contributions from serotonergic and noradrenergic effects.
Tramadol is a very weak μ-opioid receptor agonist, induces serotonin release, and inhibits the reuptake of norepinephrine. Tramadol is converted to O-desmethyltramadol, a significantly more potent μ-opioid agonist. The opioid agonistic effect of tramadol and its major metabolite(s) is almost exclusively mediated by such μ-opioid receptors. This further distinguishes tramadol from opioids in general (including morphine), which do not possess tramadol's degree of receptor subtype selectivity and which are much stronger opiate-receptor agonists. Similarly, the habituating properties of tramadol (such as they are) are arguably mainly due to μ-opioid agonism with contributions from serotonergic and noradrenergic effects.