Severe AR w/ MAOIs. CNS-active drugs; other serotonergic agents (including triptans, SSRIs, other SNRIs, amphetamines, lithium, sibutramine, fentanyl & its analogues, dextromethorphan, tapentadol, meperidine, methadone, pentazocine, tramadol or St. John's wort), drugs which impair serotonin's metabolism (eg, linezolid & methylene blue) or serotonin precursors (eg, tryptophan supplements). Increased risk of QTc prolongation &/or ventricular arrhythmias w/ some antipsychotics & antibiotics. Decreased AUC & Cmax
of indinavir. Increased AUC & Cmax
of haloperidol. Higher plasma conc w/ ketoconazole. Increased plasma conc & reduced BP-lowering effect of metoprolol. Increased AUC of risperidone. Reduced metabolism w/ CYP2D6 inhibitors. Increased levels w/ CYP3A4 inhibitors. False +ve urine immunoassay screening tests for PCP & amphetamine.