Drug reaction testing uses a

genetic test Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or ...

to predict how a particular person will respond to various prescription and non-prescription

medication A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and re ...

s. It checks for genes that code for specific

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

s which activate, deactivate, or are influenced by various drugs. There are currently four genetic markers commonly tested for: 2D6, 2C9, 2C19, and 1A2. This testing has been done for some time by drug companies working on new drugs, but is relatively newly available to the general public.

Strattera Atomoxetine, sold under the brand name Strattera, among others, is a medication used to treat attention deficit hyperactivity disorder (ADHD). It may be used alone or along with psychostimulants. It is also used as a cognitive enhancer to impro ...

is the first drug to mention the test in the official documentation, although it doesn't specifically recommend that patients get the test before taking the medication. There are four possible categories for each marker: poor metabolizer,

intermediate metabolizer Pharmacogenomics is the study of the role of the genome in drug response. Its name ('' pharmaco-'' + '' genomics'') reflects its combining of pharmacology and genomics. Pharmacogenomics analyzes how the genetic makeup of an individual affects ...

, extensive metabolizer, or ultra-extensive metabolizer. Different testing companies may call these by different names. Extensive metabolizers (that is, people who are extensive metabolizers of a given type) are the most common, and are the type of people for which drugs are designed. Up to 7% of Caucasians are poor metabolizers of drugs metabolized by the CYP2D6 enzyme. Saturday, 16 February 2019 People who cannot

metabolize Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...

a drug will require a much lower dose than is recommended by the manufacturer, and those who metabolize it quickly may require a higher dose. Some drugs, such as

codeine Codeine is an opiate and prodrug of morphine mainly used to treat pain, coughing, and diarrhea. It is also commonly used as a recreational drug. It is found naturally in the sap of the opium poppy, ''Papaver somniferum''. It is typically use ...

, will not be effective in people without the requisite enzymes to activate them. People who are poor metabolizers of a drug may overdose while taking less than the recommended dose.

References and end notes

{{Reflist Pharmacy Clinical pharmacology

See also

References and end notes