Zudena 100 mg Tablet is a medication used primarily to treat erectile dysfunction (ED). Udenafil, which is a phosphodiesterase type 5 (PDE5) inhibitor. Typically taken 30 minutes to 1 hour before sexual activity. The effects can last up to several hours, but this can vary among individuals. Zudena 100 mg works by relaxing blood vessels in the penis, allowing for increased blood flow during sexual arousal, which helps achieve and maintain an erection. Typically taken 30 minutes to 1 hour before sexual activity. The effects can last up to several hours, but this can vary among individuals.