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METABOLISM

المؤلف:  Max M. Houck، Jay A. Siegel

المصدر:  Fundamentals of Forensic Science

الجزء والصفحة:  p357-358

2026-08-10

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METABOLISM

Metabolism is a process whereby a drug or other substance is chemically changed to a different but related substance, called a metabolite. Metabolism serves at least three purposes:

1. It may deactivate the drug so that it has fewer or milder effects on the body.

2. The metabolite may be more water soluble than the parent drug. This makes it easier to eliminate the drug through urination.

3. It may convert the drug into a substance that can be used by the body’s cells for energy. This also aids in elimination of the drug. Most metabolism takes place in the liver where enzymes cause chemical changes. A drug may undergo a series of metabolic reactions whereby a first metabolite under goes further changes to form additional metabolites. An example of metabolism that renders a substance less harmful than the primary drug or substance can be found in alcohol. Ethyl alcohol, the substance that is found in beer, wine, and spirits, is a neurotoxin (kills nerve cells). The liver metabolizes alcohol to acetaldehyde, which is then metabolized to acetic acid (vinegar is a dilute form of acetic acid). Neither acetaldehyde nor acetic acid is a neurotoxin. Acetic acid is very water soluble and can be easily removed from the body in urine. It is also easily used by the cells in oxidation to produce energy.