By blocking PDE-5 enzymes,fildena 100 mg, which contains Sildenafil Citrate as its major ingredient, helps to relax blood vessels, allowing for smooth blood flow into erectile tissues of the male genital. This enzyme reduces blood flow in the male powerful organ's erectile tissues. Nitric oxide inactivates the enzyme after the c-GMP brace, and blood flow via the male reproductive organ is enhanced, improving erectile performance. similar ed pills:malegra 100 mg