Pharmacogenetic testing
PGx - testing; Pharmacogenomics - testing; Pharmacogenetics - testingPharmacogenetic testing provides information about your genes and how they control your response to certain medicines. Your genes can affect the desired result of a drug. Your provider can use the information from this test to prescribe medicines that will work best for you and produce fewer side effects.
Pharmacogenetic
Pharmacogenetics is the study of how genes affect the way medicines work in a person. Your health care provider can use the information from pharmac...
Read Article Now Book Mark ArticleGenes
A gene is a short piece of DNA. Genes tell the body how to build specific proteins. There are about 20,000 genes in each cell of the human body. T...
Read Article Now Book Mark ArticleHow the Test is Performed
Testing is done one of three ways:
- By taking a blood sample
Blood sample
Venipuncture is the collection of blood from a vein. It is most often done for laboratory testing.
Read Article Now Book Mark Article - By taking a sample of your saliva (spit)
- By collecting cells from the inside of your cheek (buccal smear)
Collecting cells from the inside of you...
A buccal (pronounced "buckle") smear is the painless removal of a sample of cells from the inside of your mouth (cheek) for study.
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How to Prepare for the Test
To prepare for the three different testing methods:
- No special preparation is necessary for the blood test.
- Do not eat, drink, smoke, or chew gum for 30 minutes before the spit test.
- Your provider may ask you to rinse your mouth before your cheek is swabbed.
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or slight bruising. This soon goes away.
The saliva test and check swab don't hurt.
Why the Test is Performed
Your provider may order pharmacogenetic testing to see if you can take certain medicines safely and how well they will work for your condition. If the results show possible side effects or that your body is resistant to that medicine, your provider can change it to a medicine your body will process better.
Normal Results
Pharmacogenetic testing results identify changes in a select group of genes. These genes control how your body responds to medicines. To select the best medicine for you, your provider will use these results, along with other information about you, such as:
- Your age
- Your lifestyle and health habits
- Other medical conditions
- Any health risks
- Any medicines you're taking
What Abnormal Results Mean
If the results show possible side effects or that your body is resistant to that medicine, your provider can change it to one your body will process better.
Risks
There is little risk in having your blood taken. Veins and arteries vary in size from one person to another and from one side of the body to the other. Drawing blood from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight, but may include:
- Excessive bleeding
- Fainting or feeling lightheaded
Fainting
Fainting is a brief loss of consciousness due to a drop in blood flow to the brain. The episode most often lasts less than a couple of minutes and y...
Read Article Now Book Mark Article - Multiple punctures to locate veins
- Hematoma (blood accumulating under the skin)
Hematoma
A bruise is an area of skin discoloration. A bruise occurs when small blood vessels break and leak their contents into the soft tissue beneath the s...
Read Article Now Book Mark Article - Infection (a slight risk any time the skin is broken)
There is no risk for the saliva test or check swab.
Considerations
Pharmacogenetic testing gives your provider more insight into which medicines may work best for you. The results don't show family medical history or if you may be at risk for specific diseases.
At this time, there are only certain medicines for which pharmacogenetics testing is considered.
References
Centers for Disease Control and Prevention website. Pharmacogenomics: What does it mean for your health? www.cdc.gov/genomics/disease/pharma.htm. Updated May 20, 2022. Accessed May 1, 2023.
Korf BR, Limdi NA. Principles of genetics. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 31.
Review Date: 6/26/2023
Reviewed By: Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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