Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes .How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. When choosing one, tell your doctor or other health care professional what your preferences are, such as cost, ease of use, how long the drug’s effects last and side effects. Your doctor will tell you not to take sildenafil if you are taking street drugs containing nitrates. You can take it in a small dose daily or in a larger dose as needed. Ask your doctor if you have any questions. A starting oral dose of 25 mg should be considered in those patients [see Dosage and Administration 2.Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in is also used to treat pulmonary arterial hypertension, a serious heart and lung drug is more popular than comparable drugs. It is available in generic and brand versions. Generic sildenafil is covered by most Medicare and insurance plans, but . Erectile dysfunction is when a man has difficulty getting an erection or keeping it long enough for sex. It’s also known as ED or impotence. It happens when not enough blood flows to the penis, preventing an erection. The frequency increases with age, affecting about 50% of men over age 40*; however younger men may also experience ED. Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour.The changes from baseline in scoring on the two end point questions frequency of successful penetration during sexual activity and maintenance of erections after penetration were highly statistically significantly in favor of VIAGRA. Viagra Still the leading brand in ED pills, Viagra should be taken at least an hour before sex and on an empty stomach. Sildenafil Viagra. VIAGRA sildenafil citrate is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to the nominally indicated amount of sildenafil and debossed on the obverse and reverse sides as follows: 25 mg. Figure 6 shows that regardless of the baseline levels of function, subsequent function in patients treated with VIAGRA was better than that seen in patients treated with placebo.