Etymology of Viagra

[Jan Ivarsson TransEdit]

Looking for the etymology of the brand name Viagra, I came upon the following:
>>Tiger urine --- sprayed backwards as a marker --- is so smelly that the Sanskrit name for tiger is vyagra, "the name derived from a verb root meaning to smell." As Watson points out,
 "This sheds an interesting new light on Pfizer's recent best-selling drug for impotent men, which is being marketed, with or without knowledge of Sanskrit, under the brand name of Viagra." >>
The source is
http://www.ralphmag.org/jacobsonsZO.html

But a Swedish source, Gösta Bergman, Ord med historia (1987, 1991, 2001), usually extremely reliable, gives a different meaning of the Sanskrit word (under the word "Tigern"):
"In the oldest Indian literature, in Atharvaveda, it is called vyaghra (the dirty yellow), which corresponds well with the rust-yellow bottom color..."

Can someone with better knowledge of Sanskrit than mine tell us which explanation is the correct one? And maybe provide us with a better etymology of Pfizer's name.

jan.ivarsson at transedit.st