What is pharmacogenomics (PGx) testing?

PGx testing is a tool used to aid in selecting appropriate medication and dosing options. It provides information on certain genetic changes or variations that affect how patients metabolize, absorb, or respond to particular medications. The results of PGx testing can help identify patients who are more likely to experience adverse events from, or respond sub-optimally to, a particular medication at standard dosages.


The Quest Pharmacogenomics Panel detects changes in multiple genes that are involved in the metabolism of a large number of commercially available medications.

What is the difference between pharmacogenomic and pharmacogenetic testing?

These two terms both relate to how inherited genetic changes impact response to medications and are often used interchangeably.​

What information will the test provide?

Pharmacogenomic tests can be used as a tool to aid in decisions about medication selection and dosing. It can identify patients who may be at increased risk for adverse or toxic effects or who may not derive the desired benefit from some medications. The Quest Pharmacogenomics Panel will provide information for a large number of commercial drugs including psychiatric, cardiac, and pain management drugs.​

How can pharmacogenomic testing help my patient?

Pharmacogenomic testing is a tool that providers can use to help identify patients at greater risk for unwanted side effects or patients who may not derive the desired benefit from a particular medication. It may help you determine those medications that have the highest likelihood of benefiting your patient.​

Which patients might be appropriate for this test?

Any patient who may begin treatment with one of the medications on the panel or patients for whom a particular medication is not achieving the desired benefit, or causing unwanted side effects.​

When is the right time to test my patient?

Since pharmacogenomic testing may predict how well an individual will respond to a medication, it may be beneficial for any patient who is receiving, or will receive, medications for which testing is indicated.​

Will medications that my patient is currently taking affect the accuracy of the results?

The accuracy of the results are not influenced by the medications your patient is taking. Potential drug-drug interactions will not be identified by this test.​

What are the benefits of a larger pharmacogenomic multigene panel versus testing only for a single gene?

​Sometimes there may be multiple genes that all play a part in the metabolism of, or response to, a particular medication. So for many drugs, testing a single gene may provide some information but may be incomplete in providing the best overall picture. Additionally, since a person’s inherited genetic makeup does not change, the information gained from a larger panel may be used throughout a person’s life if other medications are needed.

My patient has already had some pharmacogenomic testing. Can a larger panel still be helpful?

​In some cases, there may be additional genes or medications that are evaluated on different panels, so it is important to compare the testing that has already been done and determine if there are any additional genes that might provide clearer insight into the medications of interest.

What is needed to perform this test?

Specimen Type - Preferred
Whole blood in EDTA lavender top tube

Saliva and buccal swabs are also acceptable and will require collection kits that can be ordered through Quest Diagnostics

Note: DNA will be extracted from the sample and tested for changes in multiple genes.

Volume
Whole blood

  • Optimum: 5.0 mL
  • Minimum: 2.0 mL

Transport container & temperature
Original, room temperature

Unacceptable specimens
Frozen, clotted, or grossly hemolyzed blood will be rejected

Turnaround Time
7-10 days

If my patient chooses to submit a saliva sample, what are the instructions?

​You must obtain a saliva kit from Quest Diagnostics. Instructions for collecting and sending saliva samples can be found in the package inserts. The patient should fill the provided tube with saliva to the fill line. Patients should not eat, drink, smoke, or chew gum for at least 30 minutes before giving a saliva sample.

If my patient chooses to submit buccal swab, how is this collected?

You must obtain a buccal swab kit from Quest Diagnostics. Collection instructions will be found in the package insert. The patient should rub the swab against the inner cheek for about 10-30 seconds and follow instructions in the package insert. Patients should avoid eating, drinking, smoking, or chewing gum for at least 30 minutes before providing a buccal sample​

How do I order saliva or buccal kits?

For the saliva collection kit the supply order # is 200935 and the supply order # for the buccal swab is 200944.​

What are the possible results of this test?

The results will provide information about certain genetic variations that may affect how patients metabolize and, in some cases, respond to certain medications (gene-drug result). Results may be reported as Extensive Metabolizer (EM), Intermediate Metabolizer (IM), Poor Metabolizer (PM) and, in some cases, Ultrarapid Metabolizer (UM). The results of this testing can reveal some inherited or genetic changes that might make a person unresponsive or hypersensitive to a particular medication. Other genetic or inherited changes might help explain why a person might experience adverse effects from some medications. For most gene-drug results, people who are found to be Extensive Metabolizers will probably process the medication normally. Those who are Intermediate Metabolizers or Poor Metabolizers may have reduced effectiveness of some medications or might experience unwanted side-effects from some medications since the body processes the drug slower than normal. On the other hand, patients who are Ultrarapid Metabolizers may process a medication more quickly. This can also affect how well the medication works and the recommended dose.​

What medications are included in the Quest Pharmacogenomics Panel?
Why might a particular medication not be included in this testing?

While genetic variants have been found to impact drug response and/or metabolism for many different medications, information on all drugs may not be available or may still be emerging.

What genes are included in the panel?
Are there any limitations to the Pharmacogenomic test?

​For some medications, there may be clear recommendations or dosing guidelines that are established for particular genotypes or metabolizer rate. For many other medications, however, clear guidelines on dosing have not been established or are emerging. Pharmacogenomic testing is not useful for all drugs, only select drugs. Things like drug-drug interactions cannot be determined by this test and there are other factors like age, weight, and concurrent disease that can impact drug response. Therefore, it still may be necessary to try a few doses or adjust treatment accordingly. In addition, this test does not identify all genetic changes that could affect treatment decisions. Therefore, some people with normal test results may still have variants in particular genes that have not been identified.

Whom can I ask for help if I don’t know which test to order?

​For assistance with test code selection please call 1.866.GENE.INFO (1.866.436.3463).

Are resources available to me to help in the interpretation of results or to get more information about pharmacogenomic testing?

Yes, in addition to the provided laboratory report, you may also contact Genomics Services at Quest Diagnostics by calling 1.866.GENE.INFO (1.866.436.3463). This service is available for provider consultation only. Patients should not be referred to this number. There are also many independent websites (not affiliated with Quest Diagnostics) that can be referred to for additional information, including:​

https://www.pharmgkb.org

https://www.fda.gov/Drugs/ScienceResearch/ucm572698.htm

http://www.fda.gov/Drugs/ScienceResearch/ResearchAreas/ Pharmacogenetics/ucm083378.htm

https://www.nih.gov/about-nih/what-we-do/nih-turning-discovery- into-health/personalized-medicine

http://medicine.iupui.edu/clinpharm/ddis/

https://cpicpgx.org

What is the expected turnaround time?

​On average, test results can be expected within 7-10 days.

What is the cost of testing?

Quest Diagnostics participates with a large number of insurance providers. You and your patient can go to https://www.questdiagnostics.com/home/patients/cost-coverage/ insurance-providers.html to see insurance lists and third party payors, but you may wish to consult with your insurance company to see if testing will be covered.​

Call 1.866.GENE.INFO (1.866.436.3463) or email GeneInfo@QuestDiagnostics.com today for information about any of the solutions above. If calling from outside the US call 1.678.406.1198.