Decreased rate of metabolism w/ inhibitors of CYP2D6 (eg, quinidine, fluoxetine, paroxetine, amitriptyline, bupropion) & CYP3A4 [eg, macrolides (eg, erythromycin), azole antifungal agents (eg, ketoconazole), PIs (eg, ritonavir)]. Increased rate metabolism w/ CYP3A4 inducers (eg, rifampin, carbamazepine, phenytoin). Additive or synergistic pharmacodynamic effect w/ benzodiazepines & CNS depressants including alcohol; SSRIs, serotonin & SNRIs, TCAs, triptans, 5-HT
3 receptor antagonists, drugs affecting serotonin neurotransmitter system (eg, mirtazapine, trazodone) & some muscle relaxants (eg, cyclobenzaprine, metaxalone); MAOIs (eg, phenelzine, tranylcypromine, linezolid); flucloxacillin. Increased INR w/ warfarin; may produce hypoprothrombinemia w/ warfarin-like compd.