Sildamax 100mg is actively composed of Sildenafil Citrate, which is a potent PDE5 inhibitor that helps to inhibit an enzyme, which causes higher augmentation of blood flow in the whole body. The working of PDE5 inhibitors is a bit complicated. This drug works to inhibit this enzyme. It helps to stop the degradation of the cyclic Guanosine Monophosphate (cGMP). A man can attain an erection when a man is sexually stimulated. Nitric oxide is responsible for supplying enough blood to the penile organ, encouraging a strong and durable erection. Therefore, a man can last longer during sexual intercourse.