Cenforce 100 contains the same active ingredient as Sildenafil PDE5 inhibitors. A phosphodiesterase type 5 inhibitor is a vasodilator drug that works by blocking the degrading action of cGMP-specific phosphodiesterase type 5 on cyclic GMP in smooth muscle cells lining blood vessels supplying various tissues. It helps in getting and maintaining erection problems. It also helps in the treatment of erectile dysfunction and impotence in adult men. Phosphodiesterase-5 inhibitors: Phosphodiesterase-5 (PDE-5) inhibitors work by increasing the chemicals that allow the penis to become and stay erect.