Udenafil is the active ingredient in the medication zudena 100 mg tablet, which is used to treat erectile dysfunction.  Men who have this issue may lose their sexual life if they do not receive treatment for it in a timely manner. The issue arises from insufficient blood flow to the penis.

The FDA-approved medication zudena should be taken with water 20 to 30 minutes prior to having sex. Its effects last for three to five hours.