Make sure you have discussed any other medications you are currently taking or plan to take before starting sildenafil with your doctor and pharmacist. If you will be taking this medicine for pulmonary arterial hypertension, your doctor will want to check your progress at regular visits. Taking sildenafil alone will not cause an erection. Keep from freezing. Keep out of the reach of children. Do not use this medicine if you are also using a nitrate medicine, often used to treat angina or high blood pressure. Sildenafil treats erectile dysfunction by increasing blood flow to the penis during sexual stimulation.Sildenafil is used to treat high blood pressure in the lungs (pulmonary hypertension). Learn more about Revatio.1 This is a generic drug. Even if this drug is covered by Medicare or your.  · The effects may be increased because of slower removal of the medicine from the body. Leukemia (blood related cancer) or. Multiple myeloma (blood related cancer) or. Sickle-cell anemia (blood disorder)—Sildenafil should be used with caution in these patients as problems with prolonged erection of the penis may occur. Sildenafil oral tablet is available as a brand-name drug and as a generic drug. Brand names: Viagra, Revatio. Sildenafil comes in three forms: an oral tablet, an oral suspension (liquid), and an.