Other uses for this medicine This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information. Read our editorial process. Similar values for pharmacokinetic parameters were seen in normal volunteers and in the patient population, using a population pharmacokinetic approach. Bleeding disorders, history of or Stomach ulcer, or history of or—Chance of problems occurring may be increased. Flibanserin is not approved in Australia.AdEnjoy Greater Libido & Performance. Fast Express Shipping. Key facts. Sildenafil (Viagra) is a medicine used to treat erectile dysfunction (ED, also called impotence). Sildenafil works by helping to relax the blood vessels in the penis, allowing more blood to flow in and cause an erection. You should take sildenafil about an hour before planned sexual activity, so it has time to work.  · Viagra comes as an oral tablet that contains the active drug sildenafil. Sildenafil is also available in generic form. Viagra is classified as a phosphodiesterase type 5 (PDE5) inhibitor.