Perform digital rectal exam & determine prostate specific antigen (PSA). Patients w/ history of orthostatic hypotension, severe renal & hepatic impairment. Intraoperative floppy iris syndrome (IFIS) during cataract & glaucoma surgery. Concomitant w/ strong CYP3A4 inhibitors in patients known to be CYP2D6 poor metabolizers. Patients w/ history of sulfonamide allergy. May impair ability to drive & operate machinery.