Many moons ago I took an overdose. At least 30 sleeping tablets, washed down with half a bottle of Tia Maria which had several crushed paracetamol in it for good measure.
I lay down - to die - fell asleep and woke up only a couple of hours later and was extremely drowsy, as I stumbled out of bed I was so drowsy I smacked my head against a wall. I also felt extremely sick. So I went to the bathroom, to be sick, but there was just nothing there in my stomach. Then I started to hallucinate - very vividly. I'm not a drug user, never have been, I've never hallucinated before or since. So bad in fact that I woke up my housemate to tell her about these "creatures" that had infested the house. I was frightened and even phoned my parents as my housemate persuaded me not to phone Rentokill!
After a few hours these hallucinations subsided. I still felt sick for a day or two afterwards. About 2 weeks later I had a faint hallucination (the same one as after the OD) whilst sat on a bus. Then everything just resumed as before.
I don't know which part of the 'cocktail' was responsible for what, but I assume the extreme drowsiness was because of the sleeping tablets. I never had my stomach pumped, but perhaps as you said about the liver - maybe the alcohol saved me too.