Let me post a small addendum, if I may.

I have a friend working in Bolivia, and she tells me  the natives have many other uses for coca: "Coca is not addictive, it has more calcium than milk, it reduces hunger and fatigue (especially important in the case of Bolivian miners who work long hours), it has an enormous amount of nutrients found in foods, can be used as an anaesthetic, and the list goes on..."

That's all.