Fildena 150 is a drug that treats erectile dysfunction (ED) or impotence in men. Sildenafil, the main ingredient in this drug, works by inhibiting the phosphodiesterase enzyme that helps prevent the PDE-5 enzyme reaction from occurring. Increased PDE-5 enzyme response leads to vasodilation of arteries and tissues which ultimately results in getting a hard erection. You can use this medicine 1 hour before sexual intercourse and get a strong erection. Using this medicine improves your sex life. The effect of this medicine usually lasts for 4-5 hours.