Avanafil Stendra. Sexual activity may be a strain on your heart, especially if you have heart disease. The products discussed in this site may have different product labeling in different countries. Its effects often last for 4 to 5 hours. The body takes longer to absorb it after a high-fat meal or alcohol. Take sildenafil exactly as directed.25 milligrams (mg) 50 mg mg Typical dosages The following information describes commonly recommended dosages for ED. However, be sure to take the dosage your . Generic Viagra (sildenafil) is an alternative to the branded Viagra drug that can be used for treating erectile dysfunction (ED). It’s now sold by many manufacturers, including online. Never order medicines from an online pharmacy that doesn’t list its phone number and physical address, has prices that seem too good to be true, or tells you that no .