Hypotension may occur; potential risk of syncope. Exclude other conditions w/ the same symptoms as BPH; perform digital rectal exam & determine prostate specific antigen before treatment & at regular interval afterwards. Priapism, which can lead to impotence, may occur. Intraoperative Floppy Iris Syndrome during cataract surgery may occur. Concomitant use of diltiazem & warfarin, moderate or strong inhibitors of CYP2D6 (eg, fluoxetine) or CYP3A4 (eg, ketoconazole) particularly at doses >0.4 mg, carbamazepine & phenytoin, drugs for male erectile dysfunction (eg, sildenafil, tadalafil). Patients w/ end stage renal disease (CrCl <10 mL/min/1.73m
2).