Cannabis products are a pharmaceutical. You're putting drugs in your body, just a different one.
You probably aren't getting marijuana from a pharmacy and no pharmaceutical company has a patent on marijuana, which I think both technically and colloquially puts it well outside of the realm of pharmaceuticals.
https://journals.plos.org/plosone/article?id=10.1371/journal...
OP’s point seems to be pretty reasonable to me. If marijuana is outcompeting established anodynes it implies they are in the same category.