What Is Pharmacogenomics (PGx) Testing and Why It Matters

Written by Kristy Beard, MSN, APRN, FNP-C — Board-Certified Family Nurse Practitioner and Founder of Elevate Health and Wellness, serving patients across the Gulf Coast in Gautier, MS and Foley, AL.

Why the Same Medication Affects People Differently

Every patient who has ever been told that a medication 'didn't work' for them — or who experienced side effects that others on the same drug did not — has encountered the reality of pharmacogenomic variability. Drug response is not random. It is largely determined by your genetic makeup — specifically, by variations in the genes that encode the enzymes, transporters, and receptors involved in how your body processes and responds to medications. Pharmacogenomics (PGx) is the science of understanding these genetic variations and using them to predict individual drug response before a medication is prescribed.

How Drug Metabolism Works — and Why Genetics Change It

The majority of medications are metabolized by a family of liver enzymes called cytochrome P450 (CYP) enzymes. Genetic variations in the genes encoding these enzymes — including CYP2D6, CYP2C19, CYP2C9, and CYP3A4 — can dramatically alter how quickly or slowly a patient metabolizes a given drug. Poor metabolizers break down certain medications very slowly, causing drug accumulation and increased risk of side effects. Ultra-rapid metabolizers break down medications so quickly that therapeutic levels are never achieved — making the drug ineffective at standard doses. Normal metabolizers fall between these extremes and respond predictably to standard dosing. The clinical consequences of unrecognized metabolizer status can range from treatment failure and frustration to serious adverse drug reactions.

What PGx Testing Can Evaluate

A comprehensive pharmacogenomics panel can evaluate genetic variants affecting metabolism of antidepressants and anxiolytics — including SSRIs, SNRIs, and TCAs; pain medications including opioids and NSAIDs; cardiovascular medications including warfarin, clopidogrel, and statins; psychiatric medications; proton pump inhibitors; and some cancer therapies. For patients on multiple medications, PGx testing can also identify drug-gene interactions that increase the risk of adverse reactions when specific genetic variants are combined with specific drugs.

PGx Testing at Elevate Health and Wellness

At Elevate, Kristy Beard, MSN, APRN, FNP-C offers pharmacogenomics testing for patients who have experienced unexplained medication failures, intolerable side effects at standard doses, or who are beginning therapy with medications where genetic variability is clinically significant. Testing typically involves a simple cheek swab. Results are available within days and are reviewed with the patient in the context of their current and planned medication regimen to optimize therapeutic selection and dosing.

Interested in pharmacogenomics testing? Learn about our lab and testing services at Elevate in Gautier, MS and Foley, AL.

Sources: NIH. Pharmacogenomics Fact Sheet. genome.gov. | FDA. Table of Pharmacogenomic Biomarkers in Drug Labeling. fda.gov.

This article is written by Kristy Beard, MSN, APRN, FNP-C, board-certified Family Nurse Practitioner and founder of Elevate Health and Wellness. Information provided is for educational purposes only and does not constitute medical advice. Please consult a licensed healthcare provider for personalized care.