you can't be serious, only stimulating drugs should be banned. Things like nicotine and cannabis shouldn't be banned, players can do in their off time what they want. Otherwise you have to ban alcohol as well and you can't do that, can you?
No. Definitely can't ban alcohol...
However consuming alcohol an X number of hours before a match SHOULD be banned. Someone posted a youtube clip of some mug player trying to play a serious challenger/futures match obviously drunk. Can't have been great for the people who actually bought tickets to watch the match