It is, but not only. For example:

https://en.wikipedia.org/wiki/Drug A drug is a substance which may have medicinal, intoxicating, performance enhancing or other effects when taken or put into a human body or the body of another animal and is not considered a food or exclusively a food.

Even in a political sense alcohol is considered a drug. Hell, in the past many countries have even banned it like other drugs. A select few continue to do so.