History of sulfonamide allergy. Syncope. Intraoperative floppy iris syndrome. Discontinue use 1-2 wk prior to cataract or glaucoma surgery. Not to be given in combination w/ strong inhibitors of CYP3A4 (eg, ketoconazole) in patients w/ poor metaboliser CYP2D6 phenotype. Combination w/ strong (eg, ketoconazole) & moderate (eg, erythromycin) CYP3A4 inhibitors. Perform digital exam & determine PSA prior to & at regular intervals. May affect ability to drive & use machines. Severe renal impairment. Childn <18 yr.