Filitra 40 mg is a medication used to treat erectile dysfunction (ED) in men. It contains vardenafil as its active ingredient. Vardenafil is a phosphodiesterase type 5 (PDE5) inhibitor, similar to sildenafil and tadalafil, commonly used to improve erectile function. The increased blood flow to the penis allows men to achieve and maintain an erection when sexually stimulated. It's important to note that sexual arousal is necessary for the medication to be effective; it does not cause an automatic erection.