Fildena 150mg is the active medical ingredient of Fildena 150mg, belongs to the group of phosphodiesterase type 5 inhibitors. Phosphodiesterase type 5 inhibitors are widely used to treat male s*xual problems such as erectile dysfunction.A stable erection in men requires good arterial blood flow and reduced venous flow. Sildenafil citrate works by blocking the breakdown of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells that line the blood vessels that supply the main erectile tissue in the p*nis. It causes relaxation of the muscles in the p*nis region and increases blood flow to that region.