The first phosphodiesterase type 5 enzyme inhibitor was <a href="https://silagra.org/">sildenafil citrate</a> . It appeared on the pharmaceutical market in 1998 under the brand name Viagra. That is why it is
The first phosphodiesterase type 5 enzyme inhibitor was <a href="https://silagra.org/">sildenafil citrate</a> . It appeared on the pharmaceutical market in 1998 under the brand name Viagra. That is why it is