Analab Drug Interactions

CYP2D6 inhibitors: Tramadol hydrochloride is extensively metabolized by a number of pathways including CYP2D6 and CYP3A4. The formation of M1 (active metabolite) is dependent upon CYP2D6 and as such is subject to inhibition, which may affect the therapeutic response. Therefore, coadministration of tramadol hydrochloride with a CYP2D6 inhibitor (eg, fluoxetine, paroxetine, quinidine, amitriptyline) may increase concentrations of tramadol hydrochloride and reduce concentrations of M1.
CYP3A4 inhibitors: Coadministration of tramadol hydrochloride with CYP3A4 inhibitors (eg, macrolide antibiotics, azole antifungals, protease inhibitors) may decrease tramadol hydrochloride clearance. Coadministration may produce increased tramadol hydrochloride concentrations. Carefully monitor patients receiving potent CYP3A4 inhibitors (eg, ritonavir, ketoconazole, clarithromycin) for an extended period of time and adjust the dosage as need.
CYP3A4 inducers: CYP3A4 inducers (eg, rifampin, carbamazepine, phenytoin) may produce increased clearance of tramadol hydrochloride, use with caution.
Carbamazepine: Because carbamazepine increases tramadol hydrochloride metabolism and because of the seizure risk associated with tramadol hydrochloride, concomitant administration is not recommended.
SSRIs: SSRIs (Nefazodone, Venlafaxine, fluvoxamine) may inhibit tramadol hydrochloride metabolism and therefore increase toxicity. Use with caution. The serotonergic effects of tramadol hydrochloride and serotonin reuptake effects of tramadol hydrochloride and serotonin reuptake nhibitors may be additive, increasing the risk for adverse effects such as seizures and serotonin syndrome.
Warfarin: The oral anticoagulant effect of warfarin may be increased. Monitor coagulation tests and adjust dose as needed.