To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. Take sildenafil at around the same times every day. Tell your doctor if any of these symptoms are severe or do not go away: headache. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. If you are a Mayo Clinic patient, this could include protected health information. · Generic name: sildenafil (oral) [ sil-DEN-a-fil ] Brand names: Revatio, Viagra. Drug classes: Agents for pulmonary hypertension, Impotence agents. Medically . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes .  · Drugs and Supplements. Sildenafil (Oral Route) Description and Brand Names. Before Using. Proper Use. Precautions. Side Effects. Products and services. .