A little known erectile dysfunction drug called Zydena is challenging the other impotence drugs namely Viagra, Cialis and Levitra in South Korea. The drug made by the South Korean pharmaceutical firm DongA is No.3 in the erectile dysfunction drug market in Korea and has gained market share consistently since it was launched on the market to take on the other multinational impotence drugs.

Zydena was given approval for sale in Korea from the national drug authorities in November 2005 and by the beginning of 2006 it was being widely sold all over the country. The drug has proved popular in the country and now has market share of nearly 12% compared to Levitra from Bayer that has only 8.4%. This places Zydena in 3rd place behind Viagra and Cialis from Pfizer and Lilly Icos respectively. In fact the erectile dysfunction drug market is still dominated by Viagra whith nearly half of all impotence drug sales being Viagra. Lilly ICOS is in second place with a respectable 30%.

DongA Pharm is South Korea's biggest drug manufacturer and has high hopes for the future of its Zydena impotence drug following a 20 billion won investment to develop and to manufacture the drug. The local impotence market is calculated to be worth some 80 billion won and may increase as more men become aware of the benefits of using erectile dysfunction drugs.

DongA are keen to tap into international erectile dysfunction markets especially in the Unted States and the drug is going through the rigorous testing procedure of the FDA. If all goes according to plan the Zydena drug should be on sale in America sometime in 2009. The Zydena drug works in the same way as Viagra, Cialis and Levitra in that it is a PDE-5 inhibitor and improves the blood flow to the penis, thus enhancing erectile function.