Levitra (vardenafil) is an FDA-approved oral prescription medication for the treatment of erectile dysfunction (ED) in men. Levitra works in the same way by blocking the enzyme called phosphodiesterase-5 or PDE5. By blocking this enzyme the muscles in the penis can relax which allows for more blood flow and with the proper sexual stimulation can lead to an erection. It was developed by Glaxo and Bayer as a rival to Viagra®. Levitra (vardenafil) was submitted to the FDA for approval in September of 2001. The product received full release approval in August 2003 for USA.