[admin]

Originally Posted by skids

So far as I understood the drugs will go through something called 1st pass metabolism and that the drugs themselves are metabolised in the liver.

I think the confusion is coming from the word metabolism, in that drug metabolism and general metabolism as joe public thinks of it are two distinclty different things....

For instance would this statement he made hold true in relation to pharmaceuticals? " the breakdown and carrying of ANY compound and its time cycle in the body is determined directly by the metabolic rate"

Drugs do undergo first pass metabolism, but that is a phenomenon of drug metabolism. After a drug is swallowed, it is absorbed by the digestive system and enters the hepatic portal system. The absorbed drug is carried through the portal vein into the liver.

The liver is responsible for metabolising many drugs. Some drugs are so extensively metabolized by the liver that only a small amount of unchanged drug may enter the systemic circulation, so the bioavailability of the drug is reduced. Alternative routes of administration (e.g., intravenous, intramuscular, sublingual) avoid the first-pass effect.

This is obviously quite different from what most people call metabolism - they are talking about the breakdown of glucose in the body. Thus a person's "metabolic rate" or their metabolism is not related to how drugs are broken down in the body, but glucose.

Our metabolism is the rate at which the body uses energy to support all basic functions essential to sustain life, plus all energy requirements for additional activity and digestive processes.

Hope this helps