Well myself I am not a drinker, and have been in that situation., however there will be the few that are in the same boat as you or I.
I just talk amongst my friends and dance and just go with it. They are not going to harm you or bring upon a catastrophe (only God can do that) they are just there to have fun that turns rowdy when one drinks. This is always the case at a party/wedding or whatever.
If you still have a hard time enjoying yourself, you can always excuse yourself and leave, chances are they will forget why you even left or even notice you are gone, not because they dont care, but they are in their own world for that night.
Like anything though, if it gets to the point where there is violence, take your loved ones and leave quietly. Maybe alert someone before doing so.