I don't have anything to add to this node besides a correction. While Codeine is not the worlds most toxic or dangerous drug (although it does carry a risk of addiction), acetameniophen can be deadly, especially in the doses you mention. Even for adults, acetamenophen can be dangerous in doses well under a gram. If you have a liver condition, or are otherwise sick, there is a good chance that a dose of 900 to 1800 milligrams of acetamenophen can kill you.
The moral of the story is, if you want to get high on opiates, buy them on the street, where they are cut with harmless substances like strychnine and atropine.