Abstracto

The importance of biotransformation in drug metabolism

Lorena Mingwan

A chemical change in a substance (drug) that occurs because the substance is located in a biological system. Spontaneous decay of radium is not considered biotransformation, even if it occurs in the body; the chemical modification of a chemical by enzymatic attack is considered biotransformation even if it occurs in a model system in vitro. Pharmacodynamics includes the chemical effect of a drug on the body; biotransformation involves the body's chemical reaction to the drug. "Biotransformation" should be preferred to "metabolism of drugs" and the word "metabolism" should be reserved to describe the biotransformation of materials necessary for adequate nutritional status. "Biotransformation" and "detoxification" are not synonymous: the product of biotransformation can be more, not less, biologically active or stronger than the starting material.