I'm not a doctor, either, but I am an EMT. The symptoms you're describing are NOT those of an opoid OD. Were those prescription Percocet direct from a pharmacy, or black market stufff? Are you CERTAIN what he took WAS Percocet? Has he recently taken a lot of Acetominophen (like Tylenol)? Whatever, whether the symptoms are from something other than Percocet or from some other problem he has but doesn't know he has, it sounds like there may well be some kind of nuerological, or possibly cardiological, involvement. Either one would be potentially life threatening, and if I responded to a call and found someone with the signs you're reporting, he'd be immediately transported to the nearest ER. Your friend needs to get his butt to a Dr. Even if the symptoms go away, this is something that he needs to get checked out if he wants to be sure to stay alive a while.