The benefits of this medicine in comparison to other anti malarials are the side effect profile (fewer side effects), and the fact these tablets need to be taken for a shorter period of time after leaving.
The benefit of these tablets is that dosing is once weekly, as follows: 10 days before you enter the affected area, the second dose taken 3 days before and then continue to take on the same day of each week whilst there. They are continued for 4 weeks after leaving.
Sildenafil improves blood flow to the penis when sexually excited. It does this by causing relaxation of local blood vessels, thus alleviating Erectile Dysfunction, or male impotence.