Filitra 40 mg is a generic version of the brand-name drug Viagra. It contains the active ingredient vardenafil, which is a PDE5 inhibitor. PDE5 inhibitors work by blocking the enzyme that causes blood vessels to narrow. This helps to increase blood flow to the penis, which can improve erections. Filitra is also used to treat premature ejaculation, making it an effective treatment for both ED and PE.