Udenafil, a powerful PDE5 inhibitor with a distinct pharmacokinetic profile, is contained in the zudena 100 mg tablet. It provides a quick start of activity and a long duration of up to 12 hours unlike the others which are characterized by slow onset and short duration. Therefore, the zudena 100 mg tablet is considered the first choice among specialists in the UK and USA for treating erectile dysfunction because patients in these countries prefer both spontaneity and effectiv