Zudena 100 mg is a medication used for the treatment of erectile dysfunction (ED) in men. The active ingredient in Zudena is udenafil, which belongs to a class of drugs known as phosphodiesterase type 5 (PDE5) inhibitors. When a man is *****ly stimulated, an enzyme called PDE5 breaks down a chemical called cyclic guanosine monophosphate (cGMP), which is responsible for relaxing the smooth muscles in the ***** and allowing blood to flow into it, causing an erection. By inhibiting the action of PDE5, Zudena helps to increase the levels of cGMP, leading to improved blood flow to the ***** and facilitating an erection. Zudena is taken orally, typically in a tablet form, and the recommended dose is 100 mg. It should be taken approximately 30 minutes before ***** activity. The onset of action of Zudena is usually within 30-60 minutes, and its effects can last for up to 24 hours.