It’s available in 25 mg, 50 mg, and mg tablets and lasts up to 18 hours. To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and site usage information with other information we have about you. Some platforms have a digital pharmacy that ships the medication to your home, while others send an electronic prescription to your local pharmacy. The pharmacokinetics of sildenafil in patients with severely impaired hepatic function Child-Pugh Class C have not been studied [see Dosage and Administration 2. This increased blood flow can cause an erection. Finally, we checked customer reviews to better understand user experiences with each platform. The best time to take sildenafil is about 1 hour before sexual activity, but you can take the medication any time from 4 hours to 30 minutes before sexual activity.VIAGRA is available by prescription only in 25 mg, 50 mg, and mg tablets. Not actual size. TIPS FOR TAKING VIAGRA. Take VIAGRA exactly as your doctor tells you to take it. He or she will tell you how much VIAGRA to take and when to take it. Get into the mood. Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the . 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 visit. The free Discount Card works like a coupon and can save you up to 80% or more off the cost of prescription medicines, over-the-counter drugs and.