Excretion tramadol

Tramadol is available as drops, capsules, and sustained-release formulations for oral use, suppositories for rectal use, and solution for intramuscular, intravenous, and subcutaneous injection. After oral administration, tramadol is rapidly and almost completely absorbed. Sustained-release tablets release the active ingredient over a period of 12 h, reach peak concentrations after 4.9 h, and have a bioavailability of 87 to 95% compared with capsules. One 100-mg dose given to healthy volunteers resulted in plasma levels of 375 ng/ml at 1.5 h.55 Tramadol is 20% bound to plasma protein and it is rapidly distributed in the body it is mainly metabolized by O- and A-demethylation forming glucuronides and sulfates that are excreted by the kidney. 

Product information for tramadol states that the half-life was increased at least twofold in patients with cirrhosis [48]. It has also been shown that renal excretion of unchanged drug increased to 30% in cirrhotic patients, compared to 10% in healthy patients [50]. 

O-monodesmethyltramadol, A, 0-didesmethyl tramadol and their conjugates, and A-monodesmethyltramadol. O-Monodes-methyltramadol is an active metabolite and has a greater analgesic activity than the parent drug. About 90% of an oral dose is excreted in the urine in 3 days, about 30% of the dose as unchanged drug, and the rest as metabolites. The remainder of the dose is eliminated in the faeces. ... 

Tramadol is an opioid with additional actions the basis of its analgesic effects appears to derive from a combination of (relatively weak) agonist action on p-receptors, inhibition of neuronal noradrenaline uptake and enhanced serotonin release. It is rapidly absorbed from the gastrointestinal tract, 20% of an oral dose undergoes first-pass metabolism and less than 30% dose is excreted unchanged in the urine (W2 6 h). Tramadol is approximately as effective as pethidine for postoperative pain and as morphine for moderate chronic pain. 

Tramadol and metabolites Urine LLE Sodium tetraborate, pH 10.1,30 mg ml CM- S-CD Urinary excretion, stereoselective metabolism... 

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