Risk of serotonin syndrome w/ irreversible nonselective MAOIs; serotonergic drugs eg, tramadol, sumatriptan, other triptans. Monitor for serotonin syndrome w/ reversible & selective MAO-A inhibitor eg, moclobemide; reversible & nonselective MAOI eg, linezolid; irreversible, selective MAO-B inhibitor eg, selegiline, rasagiline. Higher AR incidence w/ St. John's wort-containing herbal remedies. Medicinal products lowering seizure threshold eg, antidepressants (tricyclics, SSRIs, SNRIs), neuroleptics (phenothiazines, thioxanthenes, butyrophenones), mefloquine, bupropion, tramadol. Increased AUC w/ strong CYP2D6 inhibitor eg, bupropion, quinidine, fluoxetine, paroxetine. Increased exposure w/ strong CYP3A4 (eg, itraconazole, voriconazole, clarithromycin, telithromycin, nefazodone, conivaptan, HIV PIs) & CYP2C9 (eg, fluconazole, amiodarone) inhibitors. Decreased AUC w/ rifampicin. Increased risk of bleeding w/ oral anticoagulants or antiplatelets. Enhanced effects w/ lithium or tryptophan. False +ve results in urine enzyme immunoassays for methadone.