Drug metabolism
Drug metabolism
Drug metabolism, or biotransformation, is the processby which the body changes a drug from its dosage form to a more watersoluble form that can then be excreted.
Drugs can be metabolized in several ways:
Most drugs are metabolized into inactive metabolites (products of metabolism), which are then excreted. Other drugs are converted to active metabolites, which are capable of exerting their own pharmacologic action. Active metabolites may undergo further metabolism or may be excreted from the body unchanged.
Some drugs can be administered as inactive drugs, called prodrugs, which don’t become active until they’re metabolized.
The majority of drugs are metabolized by enzymes in the liver;however, metabolism can also occur in the plasma, kidneys, and membranes of the intestines. In contrast, some drugs inhibit or compete for enzyme metabolism, which can cause the accumulation of drugs when they’re given together. This accumulation increases the potential for an adverse reaction or drug toxicity.
Certain diseases can reduce metabolism. These include liver diseases such as cirrhosis as well as heart failure, which reduces circulation to the liver.
Genetics allows some people to metabolize drugs rapidly and others to metabolize them more slowly.
Stress test Environment, too, can alter drug metabolism. For example, cigarette smoke may affect the rate of metabolism of some drugs; a stressful situation or event, such as prolonged illness, surgery, orinjury, can also change how a person metabolizes drugs.