People who use impotence drugs tend to be aware that there are three main drugs to choose from, namely Viagra, Cialis and Levitra, however the horizon is changing with other erectile dysfunction drugs beginning to make an impact and also the development of others. For example in South Korea the impotence drug Zydena from the nations biggest pharmaceutical company Dong-A is fast taking market share in the home nation and may soon begin to challenge the big 3 abroad.

The Zydena drug that was launched in 2005 has rapidly stelen market share from Viagra, Cialis and Levitra and has even overtaken Levitra in market share size. The figures show that Zydena which was only given the green light approval from the nations drug regulators less than a year ago has a 11% market share compared to Levitra's 8.4%. Levitra is made by Bayer. The Zydena drug also impacted on the sales of other erectile dysfunction drugs with Viagra's market share of 55% going under 50%  this year and Cialis losing about 5% market share from its peak of 35%. Viagra and Cialis are made by Pfizer and Lilly ICOS respectively.

New drugs are also being developed that may challenge the dominance of the big three in years to come. One example is an erectile dysfunction drug code named SK-3530 and made by SK Chemicals that is undergoing extensive testing and research. The drug is being tested in South Korea and if given the go ahead from the drug authorities it will be launched in the middle of 2007.

Another drug that ukmedix has previously reported on that may be around soon in pharmacies is being developed by Choongwae Pharma Corporation and is called Avanafil. The drug that hails from Japan is under going research and should all the clinical tests prove satisfactory expect to see the drug for sale by 2009. The size of the worldwide erectile dysfunction market worldwide is huge and investors and drug companies are hard at work chasing the financial rewards that may accrue if sufficient market share is gained.