Depending on the gaming group, you could just have a character who drinks have the player drink too... that can have unintended consequences, however. I did game with a guy once who could down so many damn beers and as he did so, he just got better and better at roleplaying. (In general, not just roleplaying a drunk). For me, I'd probably just fall asleep.
Isn't there something on Drunken Master?