Data and health care: why your pharmacogenetic results must stay up to date and follow you

Every blood test, X-ray or scan gives your health care team a snapshot of your health at one moment in time. Pharmacogenetic (PGx) testing is different: it reads genes that affect how your body handles medications, and your genes do not change. One test can guide medication choices for the rest of your life. But lifelong data only helps if two things are true: the interpretation of your results is kept up to date, and the results are available to whoever is prescribing your medication, wherever you are.

How is genetic data different from other health data?

Most lab results describe your health today and need to be repeated: cholesterol, kidney function or blood counts change over time. Your pharmacogenetic results reflect the DNA you were born with, so the test itself does not need to be repeated. What it tells you, however, applies to medications you may not need for years, such as a painkiller after surgery, an antidepressant, a blood thinner after a heart attack or an acid reducer in older age.

These differences are very common. In an analysis of nearly 490,000 people in the UK Biobank, 99.5% carried at least one gene variant that would change a medication recommendation in current guidelines. In the large European PREPARE study, using a 12-gene pharmacogenetic panel to guide prescribing reduced clinically important side effects by about 30%.

Why do pharmacogenetic results need regular updates?

Your DNA stays the same, but the science of how to interpret it keeps moving. Expert groups such as the Clinical Pharmacogenetics Implementation Consortium (CPIC) and the Dutch Pharmacogenetics Working Group (DPWG) regularly publish new and updated guidelines, and drug labels add genetic information as new evidence appears. For example:

• Changing how results are classified. In 2020, CPIC and DPWG agreed on a single method for translating CYP2D6 results into metabolizer status. Some gene variants, such as CYP2D6*10, were given a lower activity value, and people with a certain combination of variants were reclassified from normal to intermediate metabolizers. Their DNA did not change, but the advice for medications such as codeine, tramadol and some antidepressants did.
• Adding new genes and medications. The 2023 CPIC antidepressant guideline added CYP2B6 recommendations for sertraline, alongside CYP2D6 and CYP2C19.
• New medications. New medications reach the market every year, and some come with genetic information on their label.

Pharmacogenetic results must also be reviewed in the context of the medications you take now, to account for drug-drug-gene interactions. Some medications block or speed up the same enzymes that your genes control. For example, fluoxetine, paroxetine and bupropion strongly block CYP2D6, so a person with normal CYP2D6 genes who takes one of them can respond to codeine or tramadol like a poor metabolizer. A gene result read on its own, without your current medication list, can lead to the wrong advice.

A report that was accurate when it was written can become out of date. That is why a pharmacogenetic report should be treated as a living document, with updates as guidelines change and as your medication list changes. When choosing a pharmacogenetic test, select a provider that updates your report regularly and free of charge, as Pillcheck does.

Why must results be available at the time of prescribing?

Pharmacogenetic results are useful only if they are in front of the person making the decision when the decision is made. Most medications are prescribed and dispensed in the community: by family doctors, nurse practitioners and walk-in clinics, and increasingly by pharmacists, who in many provinces can now prescribe for common conditions. Many other medications are started in hospital, in the emergency department or after surgery, often by clinicians who have never seen you before.

If your results are stored in one clinic's chart, the pharmacist down the street, the surgeon in another city or the emergency physician while you travel will not see them. The medication is then chosen without the information that could have prevented a side effect or a treatment that does not work.

Why don't health records follow you in Canada?

• Clinic and hospital systems do not talk to each other. Hospitals and clinics use commercial electronic medical record (EMR) systems that are often proprietary and do not allow outside results to be easily imported or moved to another system. According to Health Canada, only 29% of primary care providers in Canada share patient information electronically outside their practice.
• Provincial databases stop at the border. Provincial drug and health information systems are run separately by each province. When you move to another province, or need care while travelling, your records often do not come with you.
• Change is slowly coming. In 2026, the federal government reintroduced the Connected Care for Canadians Act, which would require health IT vendors to use common standards so that information can be shared, and would prohibit "data blocking". Until systems are truly connected, you are the most reliable way for your results to reach every prescriber.

How can you make sure your results follow you?

• Regularly check access to your pharmacogenetic report on your phone.
• Share it with your family doctor, your pharmacist and every specialist you see, and ask them to add it to your chart or pharmacy profile.
• Bring it up whenever a new medication is suggested, including in the emergency department, before surgery, when you move or when you travel.

Is my genetic data protected?

In Canada, the federal Genetic Non-Discrimination Act makes it illegal to require anyone to take a genetic test or to disclose genetic test results as a condition of providing goods or services, such as insurance or a job. Read more about how to protect your genetic data and about precision in genetic testing.

How can a Pillcheck test help?

A Pillcheck report is designed to be shared. A pharmacist reviews your results together with all your medications and prepares recommendations that you can take to your family doctor, your community pharmacist, specialists and hospital teams, wherever you receive care. Because guidelines change, Pillcheck reports are updated as new evidence and recommendations become available, and Pillcheck notifies you when an updated report is posted, so you do not need to request one.

Pillcheck testing is performed in CAP- and COLA-accredited clinical genetic laboratories located in Canada. Pillcheck reports on 24 genes, increasing coverage with new guidelines and drug labels (see the genes tab), and covers 355 medications, which account for over 70% of dispensed prescriptions. The Pillcheck test panel ensures high accuracy for people of non-European and admixed ancestries. Your results last a lifetime, and report updates are free of charge.

Summary

• Your genes do not change, so one pharmacogenetic test can guide medication choices for life.
• Almost everyone carries at least one gene variant that affects medication recommendations.
• Guidelines and drug labels change, so pharmacogenetic reports need regular updates.
• Results must be reviewed together with your current medications to account for drug-drug-gene interactions.
• Results must be available at the time of prescribing, in primary care, pharmacies and hospitals.
• Health records in Canada often do not move between clinics, hospitals and provinces, so make sure you can access your report and share it with every prescriber.

Frequently asked questions

Do I need to repeat a pharmacogenetic test?

No. Your DNA does not change, so the test itself does not need to be repeated. The interpretation of your results should be updated as guidelines change and as you start new medications.

Will my hospital or new doctor automatically see my results?

Not necessarily. Many hospital and clinic record systems cannot import outside results, and provincial databases do not follow you to another province. Make sure you can access your report, share it, and ask for it to be added to your chart.

Who should I share my results with?

Share them with everyone who prescribes or dispenses your medications: your family doctor, nurse practitioner, pharmacist, specialists and hospital teams.

Can an insurer or employer ask for my genetic results?

In Canada, the Genetic Non-Discrimination Act prohibits requiring you to take a genetic test or to share genetic test results as a condition of providing goods or services, including insurance or employment.

References

McInnes G, Lavertu A, Sangkuhl K, et al. Pharmacogenetics at scale: an analysis of the UK Biobank. Clin Pharmacol Ther. 2021;109(6):1528-1537.

Swen JJ, van der Wouden CH, Manson LE, et al. A 12-gene pharmacogenetic panel to prevent adverse drug reactions: an open-label, multicentre, controlled, cluster-randomised crossover implementation study. Lancet. 2023;401(10374):347-356.

Caudle KE, Sangkuhl K, Whirl-Carrillo M, et al. Standardizing CYP2D6 genotype to phenotype translation: consensus recommendations from the Clinical Pharmacogenetics Implementation Consortium and Dutch Pharmacogenetics Working Group. Clin Transl Sci. 2020;13(1):116-124.

Bousman CA, Stevenson JM, Ramsey LB, et al. Clinical Pharmacogenetics Implementation Consortium (CPIC) guideline for CYP2D6, CYP2C19, CYP2B6, SLC6A4, and HTR2A genotypes and serotonin reuptake inhibitor antidepressants. Clin Pharmacol Ther. 2023;114(1):51-68.

Health Canada. The Government of Canada introduces legislation to build a more connected health care system. February 4, 2026.

Government of Canada. Genetic Non-Discrimination Act (S.C. 2017, c. 3).