Pharmacogenetic Tests
Reviewed
Also called: pharmacogenomics, pharmacogenomic testing
Pharmacogenetics (also called pharmacogenomics) is the study of how your genes affect the way your body responds to certain medicines.
Specimen: Blood, saliva, or cheek swab cells
Why this test may be ordered
- To find out whether a certain medicine could be effective for you.
- To determine how much of a medicine you need.
- To predict whether you will have a serious side effect from a medicine.
- When a medicine is not working or is causing serious side effects.
- Before treating conditions such as high cholesterol, depression, blood clot prevention, HIV, multiple sclerosis, or certain cancers.
Preparation and collection
You usually don't need any special preparations for a blood test. If you are getting a saliva test, you should not eat, drink, smoke, or chew gum for 30 minutes before the test. If you have a cheek swab, you may be asked to rinse your mouth first.
Testing is usually done on blood, saliva (spit), or a sample of cells swabbed from the inside of your cheek. At-home test kits are available for certain pharmacogenetic tests. In general, these tests should not be used for making treatment decisions because they may not be accurate.
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly. There is no risk to having a saliva test or a cheek swab.
Understanding results
Your test results will describe any changes in the gene that was tested. Changes in these genes can show how certain medicines are likely to affect you.
- No relevant gene change found: Your test results will describe any changes in the gene that was tested. Limitation: Pharmacogenetic testing cannot diagnose any conditions or tell you about your risk for developing them. Next step: Your provider will use the results of your pharmacogenetic test along with other information about your condition to recommend treatment or to make changes in your treatment.
- Gene change (variant) found: Changes in these genes can show how certain medicines are likely to affect you. Limitation: But they cannot tell you anything about your health condition. Next step: If your test results show that a certain medicine isn't right for you, your provider will consider other treatments that may help you.
- Results describe gene variants that may affect medicine response but cannot diagnose any health condition or predict disease risk.
- At-home test kits may not be accurate and should not be used for treatment decisions without consulting a healthcare provider.
- Not all medicines or health conditions have pharmacogenetic tests available.
What to do next
Talk with your provider to find out how your test results may change your treatment options.
- What specific gene variants were tested and what do they mean for my current or planned medications?
- How will these results be combined with my medical history and other factors to guide my treatment?
- Are there any medicines I should avoid based on my results?
Evidence source
Source: U.S. National Library of Medicine (MedlinePlus). Practices and reference ranges may differ in your country.