Fildena CT contains an active drug called Sildenafil Citrate, which is a PDE5 enzyme inhibitor. This drug efficiently works to stop the degradation of cGMP cyclic Guanosine Monophosphate. cGMP is a vasodilator. Therefore, the arteries began to dilate as the cGMP level increases. The body then produces nitric oxide and enhances blood supply to the penile organ, which results in an erection. Fildena CT offers four to five hours of effect.