Viagra is an oral drug for the treatment of erectile dysfunction and a selective inhibitor of guanosine-specific phosphodiesterase type 5.
Mechanism of action: By inhibiting the activity of type 5 phosphodiesterase which degrades cGMP (guanosine), the intracellular cGMP concentration is increased, thus relaxing the smooth muscle of the corpus cavernosum and increasing the arterial blood flow, leading to erection.
Extended data
Trademark dispute
The trademark case of Viagra began at 1998. Viagra, a special anti-ED drug developed and produced in Pfizer, has just come out, and the word Viagra has been used as the generic name of the drug by domestic media. Subsequently, Guangzhou willman Pharmaceutical Company first registered the Chinese trademark Viagra in China, which made Viagra from Pfizer only registered as Viagra when it entered the China market.
As a result, the two sides began a "tug-of-war" of Viagra trademarks. Until the second half of 2005, the long tug-of-war was still unclear, and Pfizer decided to take Guangzhou willman Pharmaceutical Company to court.
On June 30th, 2006, 65438+February 30th, Beijing No.1 Intermediate People's Court ruled that Pfizer could not prove that "Viagra" was its unregistered well-known trademark, so it did not enjoy the legitimate rights and interests stipulated in the Trademark Law, and rejected all the claims of Pfizer. Finally, Guangzhou willman Pharmaceutical Co., Ltd. obtained the trademarkNo.191818 "Viagra".
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