What is Fildena 100? Men with erectile dysfunction (ED) can use the drug Fildena 100 mg to treat their condition. Sildenafil citrate, a phosphodiesterase type 5 (PDE5) inhibitor, is the substance's active component. Sildenafil works by increasing blood flow to the penis during sexual stimulation, giving the penis a long-lasting erection. How does Fildena 100 mg work? Fildena works by...