How to Get a Pharmacogenetic Test in CanadaVeronika Litinski, MSc Medicinal Chemistry, MBA
Updated July 21, 2021
Precision medicine aims to replace the current one-size-fits-all model – in which therapies are developed for the “average” person. From a consumer perspective, precision means therapy tailored to you as an individual. The good news is that one arm of precision medicine, called pharmacogenetics (also known as pharmacogenomics, or PGx for short), is a well-established science that examines genetic variations in drug metabolism. In effect, once absorbed, a drug will be broken down by different enzymes, which are encoded by our genome. It helps to explain why individuals respond differently to the same medication based on their genetics. Even better, it reduces the risk of having to try one medicine, and if that doesn’t work, try another and another. When PGx insights guide prescribing, it reduces the risk of detrimental side effects and, for many people, helps avoid treatment failure.
Most of us (over 95%) have genetic variations affecting drug response
Ideally, treatment tailored to genetics will bring faster, more effective care to more people. But as experts from UCSF point out, a future in which precision medicine benefits everyone is not guaranteed largely due to the historical disparities in genetic research and affordability. However, clinical awareness and insurance coverage gaps are beginning to close.
While industry mavens are currently assessing the cost-benefit trade-offs of covering PGx testing for managing population health, pharmacogenetic reports are affordable and within reach for many Canadians. They give you and your doctor an evidence-based tool to take a closer look at your prescription medications and how your body processes them.
How often do pharmacogenetic tests need to be repeated?
Many companies offer pharmacogenetic tests in Canada. Some PGx tests focus on just one treatment area, such as antidepressants. Others, like Pillcheck, cover many drugs spanning a range of categories, including mental health, pain, cardiovascular, gastroenterology, neurology, oncology and more. Because the same set of genes is involved in processing over 70% of all medications, one Pillcheck test provides prescribing insights for an extensive list of health concerns. With PGx clinical guidelines expanding over time, Pillcheck adds new drugs regularly. Because your DNA doesn’t change, this provides lifetime value. Reports remain relevant and can be referenced anytime you and your doctor consider a new medication.
With PGx, it pays to be proactive
With every additional prescribed medication a person takes, the risk of side effects or treatment failure increases.
Case in point: the risk of contracting the COVID infection appears to increase with the dose of proton pump inhibitors (PPIs). PPIs, which treat acid reflux and ulcers, are the most prescribed medications in North America and are recommended for use at the lowest effective dose. An ‘effective dose’ can mean different amounts for different people. People who have inherently reduced CYP2C19 function (the same enzyme responsible for mental health meds) will have reduced clearance of PPIs. In other words, these people will have more difficulty removing the drug from their bodies, so the minimum effective dose will need to be adjusted accordingly.
Where do you get a pharmacogenetic test in Canada?
PGx tests are available through workplace benefits, online and select pharmacy partners, including:
- You can order directly from a company that offers a PGx service online (with or without a doctor’s prescription or requisition).
- Some community pharmacies or specialized clinics can order a PGx test on your behalf as part of their prescription management clinical services.
- Your group benefits plan may provide coverage or offer access to preferred pricing for the test. The big appeal for companies subscribing to the service, of course, is reducing employees’ sick time. https://www.cpacanada.ca/en/news/pivot-magazine/2020-09-21-personal-medicine
How much does pharmacogenetic testing cost?
Prices range from $300 – $1500 CAD, depending on the range of conditions covered and how results are delivered and maintained. Proprietary, highly specialized pharmacogenetic tests tend to cost more. Studies by independent researchers also shown a high level of disagreement in medication recommendations among them, indicating that these tests cannot be assumed to be interchangeable.
The Pillcheck service provides transparent reporting for a wide range of conditions, all according to clinically established guidelines provided by Health Canada, FDA, and CPIC, the gold standard in pharmacogenetic reporting.
Pillcheck service costs $499. Once the licensed healthcare provider reviews your results, submit the receipt as a medical expense for tax claims or reimbursement through a Healthcare Spending Account (HSA).
Pharmacogenetic testing isn’t a diagnostic service; it won’t tell you if your likelihood of developing breast cancer or Parkinson’s is higher than normal. Instead, it hones in on the specific genes involved in drug metabolism. As a user of Pillcheck, you can access your own test results and bring them to your physicians and pharmacists in any location.
Not all PGx tests are created equal. Questions to ask:
Is it informative for clinical decisions?
Test sensitivity is akin to having a high image resolution vs. low resolution. To predict something complex, such as how rapidly the liver converts the drug codeine into morphine (which can be toxic or even fatal if your liver is really, really fast at this!), we need to look at a “team” of genetic variants that work together for this process. https://www.pillcheck.ca/2017/02/14/precision-genetic-testing-high-definition-accurate-results-better-outcomes/
A truly comprehensive test would also include more rare ethnic variants – forms of genes that tend to occur at high frequency within certain ethnic groups. The Pillcheck test is optimized to maximize sensitivity and specificity (high resolution) and ensure accurate results for the ethnically diverse population in Canada.
At a minimum, a clinical-grade test covers genetic markers (such as CYP2D6) and includes copy number variants (CNV). These are common gene duplications resulting in increased enzyme activity. Some genetic testing services don’t cover enough markers, which could lead to providing false-negative results. https://www.precisionmedicineadvisors.com/precisionmedicine-blog/2019/1/16/23andme-is-offering-pharmacogenetic-testing-but-is-it-any-good
How are your PGx test results and genetic data shared?
You should not change your medications based on a pharmacogenetic test until your physician reviews your results. The Pillcheck Pharmacist Opinion Letter helps your physician apply PGx insight to optimize your treatment.
Some consumer DNA testing providers subsidize the cost of DNA analysis by selling customers’ data to their industry partners. Clinical-grade diagnostic tests are more costly because of stricter privacy regulations.
The Privacy Commissioner of Canada provides a handy checklist of questions you may ask the genetic testing company. In essence, service providers should only ask you for personal information if it is essential to delivering the service. https://www.pillcheck.ca/2019/12/27/is-your-genetic-data-safe-how-to-protect-your-genetic-data-in-the-era-of-phishing-scams-and-data-breaches/
- A Pharmacogenetic or pharmacogenomic (PGx) test reveals how you are likely to respond to a medication before it is prescribed, helping doctors choose the safest therapy quickly.
- Many private insurance plans cover the cost, and it is an eligible HSA expense when accompanied by a medication review by a licensed pharmacist.
- If the test is comprehensive, you only need to do it once and refer to the results throughout your lifetime.
Want to know more about Pillcheck and how it can help you?
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User considerations in assessing pharmacogenomic tests and their clinical support tools https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6133969/
Bousman CA and Dunlop. Genotype, phenotype, and medication recommendation agreement among commercial pharmacogenetic-based decision support tools. Pharmacogenomics J. 2018 Sep;18(5):613-622.
Bousman, C.A. et al., Navigating the Labyrinth of Pharmacogenetic Testing: A Guide to Test Selection. Clin Pharmacol Ther. 2019 Apr 20. doi: 10.1002/cpt.1432. [Epub ahead of print]
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