Common ones include: Flushing of the skin. We considered cost, medications available, and whether generic versions were offered to help reduce costs. Psychological factors like stress, depression, or anxiety can also contribute. People taking nitrates like nitroglycerin Nitrostat or isosorbide mononitrate Imdur should not take PDE5 inhibitors, as doing so could result in a dangerous drop in blood pressure. It’s available in 10 mg and 20 mg tablets. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup.According to price-comparison site test1.ru, generic Revatio will cost you as little as $ per pill, depending on where you fill your prescription. That’s . The average length of time Viagra lasts. On average, Viagra lasts between 2 and 3 hours before its effects start to diminish. Viagra can last up to 5 hours or longer depending on your dosage, your.  · GoodRx may be able to help you save over 95% off the average retail price of generic Viagra at certain pharmacies. The average retail price of the most common prescription of sildenafil could cost a couple hundred dollars, but you might be able to get that same prescription for as little as $11 with a GoodRx coupon.