Viagra is sildenafil citrate.

Viagra is an oral drug for the treatment of erectile dysfunction. It is a selective inhibitor of guanine riboside-specific phosphodiesterase type 5.

Mechanism of action: By inhibiting the activity of type 5 phosphodiesterase that degrades cGMP (guanine riboside), it increases intracellular cGMP concentration, leading to smooth muscle relaxation, increasing arterial blood flow in the corpus cavernosum of the penis, and producing erection. .

Extended information

Trademark disputes

The "Viagra" trademark case began in 1998, when the anti-ED drug "Viagra" developed and produced by Pfizer had just come out. The word "Viagra" was used by the domestic media as the common name for the drug. Subsequently, Guangzhou Wellman Pharmaceutical Company registered the Chinese trademark "Viagra" in China first, making Pfizer's "Viagra" only able to enter the Chinese market. Registered as "Viagra"

As a result, the two sides began a "tug of war" to compete for the "Viagra" trademark. Until the second half of 2005, this long "tug of war" still had no resolution. The company decided to take Guangzhou Wellman Pharmaceutical Company to court.

On December 30, 2006, the Beijing No. 1 Intermediate People's Court ruled that Pfizer could not prove that "Viagra" was its unregistered well-known trademark. , therefore, the trademark does not enjoy legal rights under the trademark law, and all claims of Pfizer were rejected. In the end, Guangzhou Wellman Pharmaceutical Co., Ltd. obtained the "Viagra" trademark No. 1911818.

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