Why the big price difference? But do you know why the two names always come up together? They include dutasteride Avodart, Jalyn and finasteride Propecia, Proscar. They enhance the effects of a chemical the body makes that relaxes muscles in the penis, called nitric oxide. The difference is that Viagra is the well-known brand-name ED drug first launched by Pfizer. Sildenafil and Viagra do the same job: they both contain the active ingredient sildenafil citrate. An inherited eye disease that affects the retina.According to price-comparison site , generic Revatio will cost you as little as $ per pill, depending on where you fill your prescription. That’s compared with . Answer. Yes, sildenafil (the active ingredient in Viagra), manufactured by Teva, is the FDA approved generic for brand Viagra. It launched on December 11, The . More about Viagra Generic Status: Lower-cost generic is available. Lower-cost generic is available. Ratings & Reviews: Sildenafil has an average rating of out of 10 from a .