They need a name they can trademark, and common words can't be trademarked. It's sort of a .com domain name problem, all the good names are already taken so you just go for something you hope is pronouncable.

> They need a name they can trademark, and common words can't be trademarked

Iunno, pretty sure a car manufacturer will sue me for trademark infringement if I try to manufacture a Beetle under my brand name.

The bigger answer is regulations in some places against the drug name inferring what it treats.

If you want to do global marketing; you gotta go for lowest common denominator: something meaningless in every language/slang.