Not indicated for use in women. Not to be used in men w/ cardiac disease for whom sexual activity is inadvisable. At least 48 hr should have elapsed after the last dose before considering nitrate administration. Patients w/ left ventricular outflow obstruction (eg, aortic stenosis & idiopathic hypertrophic subaortic stenosis); severely impaired autonomic BP control. Not recommended in patients w/ MI w/in the last 90 days; unstable angina or angina occurring during sexual intercourse; NYHA class ≥2 heart failure in the last 6 mth; uncontrolled arrhythmias, hypotension (<90/50 mmHg), or uncontrolled HTN stroke w/in the last 6 mth. Priapism-predisposing conditions (eg, sickle cell anemia, multiple myeloma or leukemia) or w/ anatomical deformation of the penis (eg, angulation, cavernosal fibrosis or Peyronie's disease). Not recommended in combinations w/ other treatments for erectile dysfunction or other PDE5 inhibitors. Symptomatic hypotension in patients taking α
1-blockers (eg, doxazosin). Nonarteritic anterior ischemic optic neuropathy (NAION). Discontinue in the event of a sudden loss of vision. Not recommended for patients w/ known hereditary degenerative retinal disorders including retinitis pigmentosa. Discontinue in the event of sudden decrease or loss of hearing. Patients w/ bleeding disorders or significant active peptic ulceration. May affect ability to drive or operate machinery. Renal impairment. Not recommended in patients w/ severe hepatic impairment (Child-Pugh class C). Pregnancy. Not to be used in childn <18 yr.