Drug reaction testing uses a
genetic test to predict how a particular person will respond to various prescription and non-prescription
medication
Medication (also called medicament, medicine, pharmaceutical drug, medicinal product, medicinal drug or simply drug) is a drug used to medical diagnosis, diagnose, cure, treat, or preventive medicine, prevent disease. Drug therapy (pharmaco ...
s. It checks for genes that code for specific
liver
The liver is a major metabolic organ (anatomy), organ exclusively found in vertebrates, which performs many essential biological Function (biology), functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of var ...
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
s which activate, deactivate, or are influenced by various drugs.
There are currently four
genetic marker
A genetic marker is a gene or DNA sequence with a known location on a chromosome that can be used to identify individuals or species. It can be described as a variation (which may arise due to mutation or alteration in the genomic loci) that can ...
s 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 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, often abbreviated "PGx," 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 o ...
,
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 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, 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.
See also
*
Medical prescription
A prescription, often abbreviated or Rx, is a formal communication from physicians or other registered healthcare professionals to a pharmacist, authorizing them to dispense a specific prescription drug for a specific patient. Historicall ...
*
Contraindication
In medicine, a contraindication is a condition (a situation or factor) that serves as a reason not to take a certain medical treatment due to the harm that it would cause the patient. Contraindication is the opposite of indication, which is a rea ...
*
Cytochrome P450
Cytochromes P450 (P450s or CYPs) are a Protein superfamily, superfamily of enzymes containing heme as a cofactor (biochemistry), cofactor that mostly, but not exclusively, function as monooxygenases. However, they are not omnipresent; for examp ...
*
Drug metabolism
References and end notes
{{Reflist
Pharmacy
Clinical pharmacology