Pharmacogenetics (PGx)— the study of how genetics affects a person’s response to drugs — is an exciting new field in healthcare. In the third article of this series on Personalized Medicine, we talked about the nuts and bolts of PGx and why it can improve the treatment of various health problems. To briefly recap, genetic differences can result in wide variations in the metabolism of medications, with the result that some individuals get little or no effect from a certain medication, while others are at higher risk of suffering severe side effects. PGX testing allows a person to learn exactly how their genetics may affect their response to drugs, and allows medication to be tailored to his or her individual needs more than ever before. In this article we’ll talk about practical issues of testing!
First, WHO should be tested and WHY?
The short answer is: Anyone who feels that personalized medicine is important to their health. A recent research study found that less than 10% of individuals tested had normal function of all five commonly-tested enzymes, and that nearly 25% of people were taking at least one medication that could be affected by these changes. And the more medications a person takes, the higher the likelihood that genetic variations in metabolism and transport of meds will come into play. The FDA has recommended genetic testing prior to starting treatment with several medications and has given about PGx considerations for nearly 150 others. Ongoing research will bring things into clearer perspective, but until then, the fact is that without genetic information, doctors have no choice but to use the old method of trial and error when prescribing medications, which subjects patients to the possibility of starting a medication that won’t work well or puts them at a higher risk of side effects. PGx information makes it possible for doctors to prescribe the right drug at the right dose, the first time.
Next, WHEN is the right time?
PGx testing can be done after a new diagnosis is made but before a medication is started. But is that the best timing? Waiting until treatment is needed may result in a delay in treatment. Some leaders in the field of PGx suggest that having test results already in hand on the day a person receives an unexpected diagnosis might be the best use of this new technology. It would allow the doctor to confidently prescribe the best medicine right away without having to wait for tests. And the great thing about PGx testing is that it provides lifelong usefulness. Because genetic information doesn’t change throughout a person’s lifetime, results will still be valid when a new diagnosis is made in the future OR when a new medication is marketed that shares the metabolic pathways of others. So on that day when a new diagnosis is made and treatment is required, wouldn’t it be great to already have the information that will allow your doctor to prescribe the right drug, at the right dose, the first time? Having test results prior to the need for drug treatment may be the most efficient way to put PGx into action, and make your healthcare more personal!
WHAT type of test?
There are several types of PGx tests. Some test just a single gene to determine if a particular medication can be used. Then there are multi-gene tests, called “panels”, which test several genes. Some panels may test certain genes based on an individual’s current medication regimen or health problems; other panels might be broader, and test all genes that are commonly involved in the metabolism and transport of medications. For those who desire a test that will give the most useful information now and into the future, an extensive, broad-spectrum PGx panel that tests all of the common genetic variants involved in medication safety and efficacy, such as the Rxight test from MDLabs, will be the most useful. Learn more.
Finally, WHERE and HOW is the test done?
PGx testing is available at some clinics, hospitals, community pharmacies and Medication Management Services, though the type of test (single-gene, specific gene panel, or broad-spectrum panel) will vary from place to place. BetterMyMeds is ready to help with a broad-spectrum PGx test kit that will provide information to help you now and into the future. Learn more.
The testing process is simple. After doctor’s order must be obtained, testing is typically done using a buccal (cheek) swab that collects cells from the inside of the cheek. These cells contain all the genetic information necessary to determine enzyme function. The mouth is first rinsed with water to make sure there’s no contamination. One swab is rubbed along the inside of one cheek and a second swab is rubbed along the inside of the opposite cheek. The swabs are then sealed in a protective container and sent to a lab to be assayed. When results are available, use the expertise of a pharmacist certified in interpreting PGx test results to get a clear understanding of their meaning.
BetterMyMeds is ready to assist you with your PGx testing needs, from providing a preprinted doctor’s order form for your doctor to review and sign, performing the test, clearly explaining the results, and providing your doctor with a copy for your health record. For more information about how we can help, go to BetterMyMeds.com!.
It’s up to you!
The second article of this series focused on the importance of communication between patients and their healthcare providers, to ensure that both sides understand goals of treatment the same way. The same goes for PGx testing — if you feel that it’s right for you, or for someone in your family, it’s up to you to discuss it with your prescriber and request a written order to perform the test. It may not be a priority for your prescriber unless he or she knows it’s a priority for you!
Make your healthcare personal!
Betty Chaffee, PharmD, is owner and sole proprietor of BetterMyMeds, a Medication Management service devoted to helping people get the maximum benefit from their medications.