The cardiovascular risks of sexual activity should be considered before beginning therapy with sildenafil; in some patients sexual activity may be inadvisable. Caution is required in patients with hepatic or severe renal impairment, and dosage reduction may be necessary. Car is also needed in patients with anatomical or hematological disorders which may predispose them to priapism. Patients who experience dizziness or visual disturbances should not drive or operate hazardous machinery. The safety of sildenafil is uncertain in patients with severe hepatic impairment, bleeding disorder, active peptic ulceration, and hypotassion, a recent history of stroke, myocardial infraction, or life-threatening arrhythmia, unstable angina, heart failure, or retinal disorders such as retinitis pigmentosa (a minority of who have genetic disorders of retinal phosphodiesterases). The manufactures advise that it should not use in these groups.
Cardiovascular disease. For mention of a consensus statement on the use of sildenafil in patients with cardiovascular disease, see above.