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 adult .You can take sildenafil with or without food. Kidney disease that needs to be treated with dialysis. Tell your doctor if any of these symptoms are severe or do not go away: headache. Tell your doctor or pharmacist if you are taking nitrates medications for chest pain such as isosorbide dinitrate Isordil , isosorbide mononitrate Monoket , and nitroglycerin Nitromist, Nitro-Dur, Nitrostat. Common ones include: Flushing of the skin. If you ever need emergency medical treatment for a heart problem, the healthcare providers who treat you will need to know when you last took sildenafil. Generic versions of sildenafil, vardenafil and tadalafil are available.Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes . 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 adult .Sildenafil Viagra. Vardenafil usually works for 4 to 5 hours. Do not mix the liquid with other medications or add anything to flavor the medication. You are encouraged to report adverse events related to Viatris products by calling U. Some people may also have ringing in their ears tinnitus or dizziness.