In November 2000 Pfizer, the makers of Viagra, suffered a blow to the successful story of their famous anti impotence drug.  A High Court ruling in London stated that its exclusive UK patent on Viagra was invalid.  This hence allow the flood gates to open for other pharmaceutical companies to produce their own versions of the drug.  The case centered on Pfizer's UK on the use of sidenafil citrate, the judge ruled that the patent was invalid for obviousness because the scientific knowledge on which the drug was based was already in the public domain.  Pfizer issued a statement that they were disappointed with the ruling but not too unhappy since it would be a long time before other similar pharmaceutical companies would be able to research, produce, and license such drugs.  However, there are many Viagra substitutes beginning to surface.

AG, a German Company has a new remedy for erectile dysfunction called Vardenafil and is looking for a partner to promote the drug (Currently GlaxoSmithKline is being courted).

Vasomax, made by an American Pharmaceutical company is also threatening Viagra' reign.  It is said to work in 1/2 the time it takes Viagra  and without any side effects sometimes observed with Viagra, according to its manufacturer Schering-Plough.  The price is expected to be the same as Viagra.  The drug works differently to Viagra in that it contains phentolamine mesylate, an alpha blocker which overrides nerves which prevent blood filling erectile tissue.  A trial in Mexico proved so popular that the drugs license was passed in record time.  The drug is also expected to be available in the UK before its launch in the United states.