Stendra avanafil : This is an as-needed medication taken 30 minutes before sex and can last up to six hours. It’s available in 10 mg and 20 mg tablets. Some examples of nitrates are nitroglycerin Nitro-Dur, Nitrostat, others , isosorbide mononitrate Monoket and isosorbide dinitrate Bidil. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. You’ll also need to fill out a medical questionnaire with answers about your medical history, current medications, and lifestyle habits. Sexual activity may be a strain on your heart, especially if you have heart disease. · For treatment of erectile dysfunction: For oral dosage form (tablets): Adults up to 65 years of age—50 milligrams (mg) as a single dose no more than once a day, 1 hour before sexual intercourse. Alternatively, the medicine may be taken 30 minutes to 4 hours before sexual intercourse. Your doctor may adjust your dose if needed.  · Teva’s version of sildenafil debuted at an average cash price of around $30 per pill, roughly 50% cheaper than brand-name Viagra. Since then, more manufacturers have brought generic versions of Viagra to market, bringing prices down even further. The average retail price of the most common prescription of sildenafil could cost a . 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 .