Remember that alcohol is not an excuse for bad decisions. You have to live with your actions. Oh, and by the way, taking advantage of someone who is drunk is called rape. So add the pills or the condoms or the diaphragms or whatever to your vacation checklist before you pack your bags. And no, not all brands of birth control pills can be used as emergency contraception either.
Several brands can, but the number of pills taken varies with the brand of pill.
You need professional medical advice to know which ones work and in what quantities. Don't self-prescribe in this situation. If you want a mixed drink, order it yourself, watch its preparation and keep it in your control and sight at all times. There are sexual predators out there and you cannot presume safety, especially in any situation where you are in a strange and unfamiliar environment. Certain corporate frogs and lizards might think so, but not most students at Davis.