Using the ED medicines we prescribe puts you at greater risk of severe reactions such as extreme dizziness, fainting, heart attack, and stroke. Popular ED medications found online include: Viagra sildenafil : As the first FDA-approved PDE5 inhibitor for ED, sildenafil is taken 30 minutes to four hours before sexual intercourse to help achieve and maintain an erection. Men who are taking nitrates or nitroglycerin Those with hypotension Men who have heart disease or heart failure ED can be the first sign of other health conditions, including cardiovascular disease and diabetes. These include chest pain and tightness, shortness of breath, extreme lightheadedness, and swelling in the hands and feet. Privacy: Confirm that your personal data and payment details are confidential. You should also call your insurance company to see if they cover erectile dysfunction medications.Cart. Transfer your prescription for Sildenafil (Generic for Viagra, Oral Tablet) on Amazon Pharmacy. FREE SHIPPING for Prime members. Email With the VIAGRA Savings Card, eligible patients may save 50% on up to 12 prescriptions of brand-name VIAGRA per year.* *Eligible patients could save up to . According to price-comparison site , generic Revatio will cost you as little as $ per pill, depending on where you fill your prescription. That’s .