Udenafil is a drug used in urology to treat erectile dysfunction. It belongs to a class of drugs called PDE5 inhibitor, which many other erectile dysfunction drugs such as sildenafil, tadalafil, and vardenafil also belong to. It was developed by Dong-A Pharmaceutical and is marketed under the trade name Zydena. It is not approved for use in the United States by the U.S. Food and Drug Administration.

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