Small case studies in pregnant women with PAH indicate a low risk of harm, though caution is warranted. If you often forget doses, it may help to set an alarm to remind you. For erectile dysfunction, it’s best to take sildenafil on an empty stomach. The usual adult dose is 20mg taken 3 times a day. Wat Jed Yod Temple On the territory of the temple there is a large sacred Bodhi tree, under which seven Buddha figures in various poses are comfortably located. If you experience a prolonged or painful erection for 4 hours or more, contact your doctor immediately. Take sildenafil up to 4 hours before you want to have sex.Viagra (sildenafil) is a brand-name prescription drug that’s used to treat erectile dysfunction (ED). Learn about side effects, warnings, dosage, and more. Medicare coverage and pricing details for Sildenafil. Learn more about Medicare prescription drug plans and savings with GoodRx. Type your drug name (like .  · Compare prices. Drug prices vary by pharmacy. Use GoodRx to find current prices and discounts. Get free coupons. GoodRx coupons can help you pay less than the cash price for your prescription. Show to your pharmacist. It’s easy. Just bring your free coupon to the pharmacy when picking up your prescription.