What could make my friend act so bizzare after drinking PJ at a frat party?

My friend drank the same PJ(mixed drink) at this frat party as my other friends(I didn't drink). We watched them pour the drinks. Later she starts to look at us weird and tell us we are being strange and wants to leave us. I try to walk her back to her dorm so she doesnt have to walk alone because I told her it wasn't safe. She gets mad at me for wanting to walk her, then tells me im being embaring and she is going to leave. I yell at her telling her not to leave without me and she gets even more upset with me. This odd behavior continued as I finally got her to let me walk back with her, but she sped-walked all the way there trying to lose me. She gets pissed and locks me out of her room once we get there....What could possibly have been put in her drink? Please respond ASAP