According to the Harry Potter Wikia, there is a sub-department in the Department of Magical Law enforcement named the Department of Intoxicating Substances that deals with alcohol abuse. What about Drug abuse and drug pedalling? Would this department deal with this as well (since drug is intoxicating) or will it be dealt with by the Improper Use of Magic Office? The drug I'm mentioning in my story is a magical drug made with magical ingredients, not the Muggle drugs.
Thanks in advance!