I didn't state that very well. Let me try again. A healthy person can develop tolerance for alcohol and some medications such as codeine. They will require more alcohol/meds to get the same effect they initially experienced. If you stop taking the alcohol/med and are healthy the tolerance will go away. But if you have some damage to the liver you may still have some tolerance. And in severe damage to the liver you will experience intoxication with low amounts because the liver cannot process the alcohol/drug efficiently.

Does that make more sense?

The book that is informative is
Under The Influence: A Guide to the Myths and Realities of Alcoholism by Dr James Milam

on ebay http://cgi.ebay.com/Under-Influence-...f#ht_499wt_928