Husband took oxycodone. What to do?

My husband has been prescribed Percocet by his doctor for shoulder pain. He has to get surgery but it’s a bad time for him to be getting surgery right now so he’s waiting for a few months. He was given Percocet to manage the pain but he is very careful about taking it and only does when he really needs to. Well we switched insurance companies and they aren’t approving it now for some reason. So his doctor prescribed Percocet that doesn’t have acetaminophen in it. He took one tonight when he got home and has been sleepy and not right ever since. He is only half there and isn’t being responsive like he’s drunk or something. He only took the prescribed amount but I’m worried now. I don’t think he’s in danger or anything, but I really don’t want him taking these again. Has anyone had an experience like this? When he wakes up tomorrow, I’m going to talk to him about it. Any help is appreciated. Thank you.