This boosts blood flow and helps you get an erection from sexual activity. You can take this medicine with or without food 30 minutes before sex, depending on the dose. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. The patent on Revatio indicated for pulmonary arterial hypertension rather than erectile dysfunction expired in late They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar. As with sildenafil, a high-fat meal or alcohol keep the body from absorbing it as quickly.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 . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes . Q&A. Drug Images. What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a prescription drug that’s used in .