Erectile dysfunction is the inability to achieve or maintain an erection sufficient for sexual intercourse. Fildena contains sildenafil citrate as its active ingredient, which belongs to a class of drugs known as phosphodiesterase type 5 (PDE-5) inhibitors. Sildenafil citrate works by inhibiting the action of the enzyme called PDE-5, which is responsible for the degradation of a compound called cyclic guanosine monophosphate (cGMP) in the penis. These are the best tablets for sex life. Fildena is to be used once a day. Fildena Pill to treat this problem. It is used to treat the problem of impotence. The effect of this medicine lasts for 4 to 6 hours.