Tramadol manufacturers

Approximately one-third of both dihydrocodeine and tramadol are eliminated by the kidneys. Manufacturer s data for tramadol suggest that in hepatic or renal impairment the increase in half-life should be relatively low as long as one of these organs is functioning normally [48]. 

An unpublished study by the manufacturers found that the maximum plasma levels and the elimination half-life of a single 50-mg dose of tramadol were reduced by 50% by carbamazepine 400 mg twice daily for 9 days. It is likely that carbamazepine increases the metabolism of tramadol. On the basis of this study the manufacturers say that the analgesic effectiveness of tramadol and its duration of action would be expected to be re-... 

In an unpublished study on file with the manufacturers, cimetidine increased the AUC of tramadol hy 15% to 27% and decreased the total body clearance by 14% to 22% in healthy subjects. The manufacturers say that these changes are not clinically significant. ... 

A placebo-controlled study in 12 healthy subjects found that quinidine 50 mg had virtually no effect on the analgesic effects of tramadol 100 mg but it inhibited its effect on pupil size. The manufacturers say that quinidine increases the tramadol AUC and maximum level by 25%, but this is within the normal pharmacokinetic variation seen with tramadol. Tramadol is partially metabolised to the active metabolite O-desmethyltramadol (which affects opioid receptors), by the cytochrome P450 isoenzyme CYP2D6, and it is this enzyme that is inhibited by quinidine. Blockade of the production of this metabolite appears to have little effect on the analgesic effect of tramadol. No special precautions seem to be needed. 

Because the concurrent use of more than one serotonergic drug has rarely resulted in the serotonin syndrome , (p.9), the manufacturer advises caution if duloxetine is used with tricyclic antidepressants , (p.l240), or other antidepressants , (above), triptans, tramadol, and pethidine. ... 

According to the manufacturer s prescribing information, the initial recommended dosage of tramadol ER is 100 mg once daily, with titration in 100 mg increments every 5 days (if required) up to a maximum dosage of 300 mg once daily. The drug is to be used in adults only, and may be administered without regard to food. 

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