Viagra On this Page Treatment & Uses Safety Information Before Using Treating Overdose Side Effects Generic Name: Sildenafil (sil-DEN-a-fil) Brand Name: Viagra Viagra is used for: Treating erectile dysfunction (ED). It may also be used for other conditions as determined by your doctor. Viagra is a phosphodiesterase type 5 (PDE5) inhibitor. It works by helping to increase blood flow into the penis during sexual stimulation. This helps you to achieve and maintain an erection. Do NOT use Viagra if: you are allergic to any ingredient in Viagra you have been advised by your doctor to avoid sexual activity because of heart problems you are taking nitrates (eg, isosorbide, nitroglycerin) in any form (eg, tablet, capsule, patch, ointment), or nitroprusside you use certain recreational drugs called "poppers" (eg, amyl nitrate or nitrite, butyl nitrate or nitrite) you take another PDE5 inhibitor (eg, tadalafil, vardenafil) or another medicine that contains sildenafil Contact your doctor or health care provider right away if any of these apply to you. Before using Viagra : Some medical conditions may interact with Viagra . >>>