Sildenafil is a remedy by oral, that was approved by FDA (Food and Drug Administration – AUA) in 1998 and it was one big advance in the Erectile Dysfunction treatment. It is presented in doses that changes from 25, 50 and 100 mg. Only the doctor will know to indicate which how much is the most proper for each case.
It will work well in young patients without serious pathology, it is a selective vasodilator of the arteries from the corpora cavernosa, acting as selective inhibitor on PDE5, thus favoring, an erection of the corpora cavernosa. In patients with more serious pathologies or more elderly it's utilization won't be so indicated, because “Alprostadil” will be more efficient, or even the use of inflatable or malleable penile prosthesis.
For some patients the drug does not offer many side effects, however, it is contraindicated for people with heart problems, or who use nitrate... The most common side effects are tachycardia, headache, hypotension, gastritis, diarrhea, visual disturbances and in cardiac patients or hypertensives that uses nitrate, the risk of problems is high.
Every person who wants to use Sildenafil should see a specialist for a clinical analysis before. This drug is contraindicated for patients who make concomitant use of nitrates and for rare visual retinitis pigments disease and should only be used with guidance and prescription. Never medicate yourself.