In the average healthy human being alcohol is metabolized by the
liver at the rate of about one standard drink (0.6 oz ethanol)
per hour. In people who frequently engage in heavy drinking
alcohol tolerance develops. Changes occur in the brain and the
liver which work to adapt them to the steady presence of
alcohol. When alcohol tolerance develops people need to drink
much more alcohol to get the same effect as they used to.
Reverse Tolerance occurs when a heavy drinker develops liver
damage and the liver no longer produces as great a quantity of
the enzymes needed to break down alcohol in the body as it did
before. Since people with a lot of alcoholic liver damage can no
longer metabolize alcohol very well, these people can get very
intoxicated on small quantities of alcohol--much smaller
quantities than are needed to affect the person who rarely
drinks. This phenomenon is known as Reverse Tolerance. The way
that Reverse Tolerance can develop over a lifetime is
illustrated by the curve in Figure 1. As we can