Mixing meds ?

Was at a ‘party’ with my family. My stepdad has chronic pain so he takes daily pain meds like Xanax, oxycodone, hydrocodone, and a couple more than I don’t know for sure. He never drinks but decided he would drink quite a bit and acted more drunk with less drinks than everyone else. He seemed really wobbly, disoriented, and just loopy. He just acted too fucked up and I’m worried about him. How much danger did he put himself in ??