[afsnco]

The word is from “pharmakon” which means “a drug, that is, a spell-giving potion.” It appears to me that all recreational drugs fall into this category. They produce an altered state of consciousness. These “potions” leave their users “spellbound.” That’s why drinking alcohol to drunkenness is also forbidden.

[Durus]

That is a gross oversimplification of the term. Pharmakós was an ancient Greek religion known for human sacrifice. They were known as poisoners and using drugs to induce "religious" experiences. The term later expanded to those that used/sold fake remedies. To then limit it to druggies or drug dealers needlessly limits the term and doesn't (probably) encompass the full intentional use of the word.

Being drunk as far as I can see is not forbidden, while being a drunkard is. There is a difference.