May increase exposure of & increase risk of adverse effects w/ clozapine. May increase exposure of nebivolol, donepezil, brexpiprazole, doxorubicin, amitriptyline, tamsulosin, oxycodone, propranolol & CYP2D6 inhibitors. May prolong QT interval & increase exposure of eliglustat, fluoxetine. May increase exposure & plasma conc of desipramine, flecainide, doxepin, clomipramine, imipramine, vinblastine, protriptyline, amoxapine, nortriptyline, thioridazine, carvedilol, or trimipramine. May increase bioavailability & risk of hypocalcemia w/ ketoconazole. May increase exposure & plasma conc w/ indinavir, erythromycin, ritonavir, clarithromycin, nelfinavir, nefazodone, atazanavir, telithromycin, voriconazole, saquinavir, fosamprenavir, or delavirdine. May increase plasma levels of tamoxifen.