Sildenafil usually should not be taken more than once every 24 hours. Liquid sildenafil will usually be made up for you by your pharmacist. Before taking sildenafil, tell your doctor and pharmacist if you are allergic to sildenafil, any other medications, or any of the ingredients in sildenafil tablet or suspension. How should this medicine be used? Take sildenafil exactly as directed. The medicine will come with a plastic syringe or spoon to help you take the right amount. · Sildenafil: 20 mg / 30 tablets. *Lowest online price at national pharmacy chains Costco, CVS, RiteAid, Walgreens and Walmart as of 1/19/ Prices vary by location and pharmacy, see test1.ru for actual pricing in your area. Visit test1.ru to find your nearest coupon prices. Intravenous Solution 10 mg/ mL sildenafil intravenous solution from $ for milliliters Oral Powder For Reconstitution 10 mg/mL sildenafil oral powder for reconstitution from $7, for milliliters Oral Tablet 20 mg sildenafil oral tablet from $ for 10 tablets 25 mg sildenafil oral tablet from $ for 30 tablets. The usual dose is 50mg, when you need it. Do not take it more than once a day. The dose can be increased to mg or decreased to 25mg depending on its effect. Take sildenafil up to 4 hours before you want to have sex. For sildenafil to work properly, you’ll need to be sexually excited.