Fildena Chewable 100 mg contains Sildenafil Citrate, a drug from the PDE5 inhibitor class. It is primarily used to treat erectile dysfunction (ED) by enhancing blood flow to the penis during sexual arousal. Sildenafil works by relaxing the smooth muscles in blood vessels, which allows increased blood flow to specific areas of the body. In the context of erectile function, this means more blood can enter the penile tissue, facilitating the ability to achieve and maintain an erection.