To elaborate slightly on my previous post and not get too hounded by Curtis, et al. I will post something slightly less black and white on the subject.
I know people use alcohol in order to "loosen things up." I understand that and have no problems with it. However, any more than one or two drinks, depending on body mass and all, is approaching a safety limit. I would seriously discourage ANY BDSM-related activities after this stage has been reached.
Also, any other non-OTC drugs (marijuana, cocaine, etc.) should NEVER be used in conjunction with a BDSM scene. I don't give a damn if your submissive begs to be tied up and beaten to a bloody pulp while you snort an entire brick of coke out of her pussy, do not do it! If anything goes wrong, and it very likely will, you leave yourself open to all sorts of legal ramifications. More importantly, you give the BDSM community yet another black eye and we have plenty of them as it is.
So, keep your partying and your bondage seperate. Act like a responsible adult while you have someone's life literally in your hands.