If you are taking sildenafil to treat erectile dysfunction, you should know that it does not cure erectile dysfunction or increase sexual desire. 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. Take sildenafil exactly as directed. Other uses for this medicine This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Before starting, stopping, or changing any medications while taking sildenafil, please get the advice of your doctor or pharmacist. Do not take more or less of it or take it more often than prescribed by your doctor.Brand names for sildenafil include Viagra, Revatio, and Liqrev. The cost for sildenafil oral tablet mg is around $10 for a supply of 2 tablets, depending on the pharmacy you visit. Valid at all major chains including Walgreens, CVS Pharmacy, Target, WalMart Pharmacy, Duane Reade and 65, pharmacies nationwide. No manufacturer. 2 days ago · Generic Viagra is also available through Hims starting at $4 per dose. Product details Usage: take as needed ; Effectiveness: lasts 2–5 hours; Returns: no returns. Rarely reported side effects include: an erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, get medical help right away. If it is not treated right away, priapism can permanently damage your penis. sudden vision loss in one or both eyes.