How Pharmacogenetics Testing Supports Personalized Prescribing
Prescribing the right medication is not always straightforward. Patients can respond differently to the same drug and dose, sometimes experiencing limited benefits or unexpected side effects. Pharmacogenetics testing helps support personalized prescribing by examining how an individual’s genetic makeup may influence medication metabolism and response. At OncoHelix, pharmacogenetics (PGx) testing is offered as part of a precision diagnostics portfolio designed to support informed, evidence-based medication decisions for healthcare providers across Canada.
What Is Pharmacogenetics (PGx) Testing?
Pharmacogenetics testing investigates how genetic variation may affect how the body processes certain medications. Genes play a role in how drugs are absorbed, metabolized, activated, or cleared. When a medication is metabolized too quickly, too slowly, or not as expected, the prescribed dose may be ineffective or increase the risk of adverse effects.
A pharmacogenetic test analyzes selected genes known to be involved in medication response. Because these genetic variants do not change over time, PGx results can be stored and referenced throughout a patient’s life as medications are added or adjusted.
Why Personalized Prescribing Matters
Traditional prescribing relies on clinical guidelines, population-level evidence, and trial-and-error adjustments. While this approach is effective for many patients, it does not account for genetic differences that may influence medication response. Pharmacogenetic testing has gained recognition among clinicians and pharmacists as a tool to support evidence-based medication management, particularly when paired with curated guidelines and clinical decision support tools (Mukerjee et al., 2019).
Pharmacogenetics testing adds another layer of information that may help clinicians:
· Identify patients at higher risk of adverse drug reactions
· Support optimal medication selection
· Inform dosing considerations for certain medications
· Reduce unnecessary medication changes over time
PGx testing is not intended to replace clinical judgment. Instead, it is used alongside patient history, diagnosis, current medications, and clinical guidelines to support personalized prescribing decisions.
How Pharmacogenetics Supports Clinical Decision Making
Pharmacogenetics testing provides structured insights into gene–drug relationships that may be clinically relevant. Studies have also shown that pharmacogenetic panels and their associated clinical support tools can vary in gene coverage and interpretation, highlighting the importance of understanding how test design and reporting influence clinical use (Mukerjee et al., 2019).
In practice, PGx results can support:
· Medication selection by highlighting drugs that may be more suitable based on genetic profile
· Dose considerations where genetic variation affects drug metabolism
· Risk awareness for potential side effects or reduced therapeutic response
· Long-term medication planning, as results can be reused for future prescribing decisions
Because PGx information is stable over time, it can support ongoing medication management across multiple care settings.
Pharmacogenetics Testing at OncoHelix
OncoHelix offers pharmacogenetics testing to support personalized medication strategies across a broad range of therapeutic areas.
The OncoHelix PGx panel is designed to:
1. Guide optimal medication selection
2. Identify potential risk of adverse drug reactions
3. Support informed clinical decision making
Testing is completed using a non-invasive buccal swab sample. Once analysis is complete, both the patient and the ordering clinician receive an electronic PGx report summarizing relevant findings. Reports are designed to be clear, clinically focused, and easy to integrate into existing workflows.
When Pharmacogenetics Testing May Be Helpful
While clinical use varies by practice and patient population, pharmacogenetics testing may be considered when:
· Patients have experienced side effects or limited response to medications
· Multiple medications are being managed concurrently
· Long-term medication planning is required
· Clinicians want additional information to support prescribing decisions
PGx testing can be especially useful in complex cases where medication response has been difficult to predict.
Integrating PGx Testing Into Clinical Practice
Implementing pharmacogenetics testing typically involves:
· Identifying patients who may benefit based on clinical context
· Completing the PGx requisition with relevant medication and diagnostic details
· Collecting a buccal swab sample and shipping it to the laboratory
· Reviewing results alongside clinical history and prescribing guidelines
Because results can be referenced over time, a single PGx test may support future prescribing decisions as a patient’s medication needs evolve.
Frequently Asked Questions
Is pharmacogenetics testing a replacement for clinical judgment?
No. PGx testing provides additional information to support prescribing decisions and should always be interpreted in the context of the full clinical picture.
Do pharmacogenetics results change over time?
No. Genetic variants remain stable, so PGx results can often be used throughout a patient’s lifetime.
Who receives the PGx report?
Both the patient and the ordering clinician receive an electronic report once testing is complete.
Conclusion
Pharmacogenetics testing supports personalized prescribing by providing genetic insights that may help clinicians better understand medication response and risk. When used alongside clinical expertise and established guidelines, PGx testing can contribute to safer, more informed medication management.
OncoHelix supports healthcare providers across Canada with pharmacogenetics testing designed to fit real-world clinical workflows and precision medicine approaches.
For more information about pharmacogenetics testing or other molecular diagnostics, contact OncoHelix.
Reference
Mukerjee, G., Huston, A., Kabakchiev, B., Piquette-Miller, M., van Schaik, R., & Dorfman, R. (2019). User considerations in assessing pharmacogenomic tests and their clinical support tools. The Pharmacogenomics Journal, 19, 287–298. https://doi.org/10.1038/s41397-018-0049-1