Assess for CV conditions prior to treatment. Discontinue use if sudden visual defect or decreased or loss of hearing occur. Patients w/ preexisting CV risk factors. Increased risk of acute NAION. Patients w/ anatomical deformation of penis eg, angulation, cavernosal fibrosis or Peyronie's disease, or conditions predisposing to priapism eg, sickle cell anemia, multiple myeloma or leukemia. Galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption. Concomitant use w/ antihypertensives, α1
-blockers, other PDE5 inhibitors, CYP3A4 inhibitors. May affect ability to drive & use machines. Hepatic impairment. Not recommended for once-daily dosing in severe renal impairment. Not to be used in women. Avoid use during pregnancy. Not to be used during lactation. 5 mg: Rule out prostate carcinoma prior to treatment.