In 2011, 21,649 emergency room visits in the United States were related to tramadol. Interactions
Tramadol can interact with other medications with similar mechanisms of action. Tramadol acts as a serotonin-norephinephrine reuptake inhibitor and thus can interact with other serotonergic medications (selective serotonin reuptake inhibitors, serotonin–norepinephrine reuptake inhibitors, tricyclic antidepressants, triptans, cough and cold medications containing dextromethorphan, herbal products containing St. John’s wort, and medications that inhibit the metabolism of serotonin, such as monoamine oxidase inhibitors) and, in combination, may lead to serotonin syndrome. It may also make some  serotonergic antagonist anti-emetic medications (ondansetron) less effective.Tramadol also acts as an opioid agonist and thus can increase the risk for side effects when used with other opioid analgesics (such as morphine, pethidine, tapentadol, oxycodone, and fentanyl).Tramadol is metabolized by CYP2D6 enzymes which contribute to the metabolism of approximately 25% of all medications. Any medications with the ability to inhibit or induce these enzymes may interact with tramadol.Tramadol increases the risk for seizures by lowering the seizure threshold. Using other medications that lower seizure threshold (such as antipsychotic medications or amphetamines), further increases this risk. Pharmacology
Mechanism of action
Tramadol induces analgesic effects through a variety of different targets on the noradrenergic system, serotoninergic system and opioid receptors system. Tramadol exists as a racemic mixture, the positive enantiomer inhibits serotonin reuptake while the negative enantiomer inhibits noradrenaline re-uptake, by binding to and blocking the transporters. Tramadol has also been shown to act as a serotonin releasing agent.
Randomization was stratified by chemotherapy choice (capecitabine, eribulin, gemcitabine, or vinorelbine), number of lines of therapy in the metastatic setting (≤ 2, > 2), and number of metastatic sites (≤ 2, > 2). The trial was conducted at 166 sites in the United States and 16 other countries.It was approved for medical use in the United States in December 2020. References
External links
"Margetuximab". Drug Information Portal. U.S. National Library of Medicine.