Fildena 50 is a medication used for the treatment of erectile dysfunction (ED) in men. It contains sildenafil citrate as its active ingredient. Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor, and it works by increasing blood flow to the penis during sexual stimulation. Fildena 50, like other medications in the same class (PDE5 inhibitors), helps relax the smooth muscles in the blood vessels of the penis.