Some illegal “street” drugs called “poppers” such as amyl nitrate, butyl nitrate, or nitrite. May make this condition worse. The medicine will come with a plastic syringe or spoon to help you take the right amount. Do not take it more than 3 times a day. Dosing The dose of this medicine will be different for different patients.Brand Names: Revatio, Viagra Sildenafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). Learn more about sildenafil oral. 1 Sildenafil is used to treat. Want to see these pharmacies on a map and filter by available services? How much does sildenafil citrate or revatio cost near you? Find the best sildenafil citrate or revatio . Viagra is available in a generic version. Read on to learn about Viagra and cost, as well as how to save money on prescriptions. If you’d like other information about Viagra, refer to this article.