Pharmacogenomics vs. Pharmacogenetics: What's the Difference?

Pharmacogenomics and pharmacogenetic specialists interpret and research genetic information, so patients receive effective, safe medical care tailored to their unique genetic needs.

But what's the difference between these similar-sounding careers? Read on to learn how these fields differ, how they're applied in clinical settings, and their important role in the future of healthcare and precision medicine.

Pharmacogenetics is the study of how single genes respond to drugs and medicine. Although the term wasn’t coined until the 1950s, the field dates back more than 2,500 years, to Pythagoras’ observation of G6PD deficiency (also known as favism). 

By identifying individual genetic variations, healthcare providers can better predict how a person will respond to a drug. This, in turn, allows providers to create more effective, individualized treatment plans for their patients that move away from “one-size-fits-all” approaches. 

Pharmacogenomics (or PGx) is a relatively new field within precision medicine that emerged in the 1990s with the Human Genome Project. It combines pharmacology and genomics (the study of genomes) to examine how a person’s entire genome (or multiple genes) affects their response to medicines, along with other patient-specific factors like environment and lifestyle.

Although pharmacogenomics and pharmacogenetics are similar-sounding terms that are often used interchangeably, there are key differences between each area that we’ll briefly touch on, including:

• Focus and scope
• Common applications

The primary difference between pharmacogenetics and pharmacogenomics is their focus and scope. Pharmacogenetics focuses on how a single gene affects a person's response to a drug, while pharmacogenomics examines how a person’s entire genome influences their response to medications.

Essentially, pharmacogenomics is a more comprehensive field that includes pharmacogenetics because it considers the cumulative effect of multiple genes on drug efficacy and safety.

The two fields also differ in how they are applied in clinical practice. 

For instance, because pharmacogenetics focuses more narrowly on single-gene interactions with drugs, it’s often used to determine the appropriate drug dosage for a patient and minimize side effects. In the healthcare setting, this might look like a doctor conducting a genetic test on the genes CYP2C9 and VKORC1 before prescribing a patient warfarin, to mitigate an adverse reaction that increases the risk of dangerous bleeding or hemorrhaging.

In pharmacogenomics, testing supports more complex, multi-drug treatments by analyzing multiple genes and genome-wide interactions. For example, it is commonly used in breast cancer treatments to evaluate both tumor genetics and an individual’s entire genetic makeup to determine appropriate therapies.

Both pharmacogenomic and pharmacogenetic testing begins with a healthcare provider collecting a patient sample, usually a blood sample or buccal swab. After collection, the test is sent to a laboratory for processing and analysis.

Researchers note that testing in both fields spans a wide spectrum. Generally, however, because pharmacogenetics focuses on single genes, testing targets specific genes and predefined panels of single nucleotide polymorphisms (SNPs) using technologies like Polymerase Chain Reaction (PCR)-based methods.

Pharmacogenomic testing, on the other hand, uses more complex, broad-scale profiling technologies, such as Next-Generation Sequencing (NGS), which analyzes complete genomic sequences and draws on large genetic databases.

The next step requires a healthcare provider to interpret laboratory results. A report identifies the genes or genomic variants that affect drug metabolism. Using these results, healthcare providers can consult Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines to determine what the results mean for treatment, including suggested medicines and dosages.

Pharmacogenomic and pharmacogenetic testing results are lifelong, so it’s important that patients are educated on their implications; these results must also be applied to a patient’s electronic healthcare record for future care and providers. 

The benefits of pharmacogenomic and pharmacogenetic testing are extensive for patients and their medical teams, including that it can:

• Lead to safer and more effective treatment outcomes
• Lessen the chances of adverse drug reactions (ADRs) and side effects
• Lower overall healthcare costs
• Provide opportunities for advanced disease screenings

Benefits also exist on a wider scale: scientists and drug developers can use large amounts of genomic data to create medicines targeted to specific populations, enabling more personalized and effective drug development.

Despite the many benefits pharmacogenetics and pharmacogenomics bring to patient care, both fields still face challenges, including:

• Lack of standardization
• Privacy and data concerns
• Poor insurance reimbursement

One challenge both fields face is the need for worldwide standardization, including testing practices, regulations, and clinician guidelines. By establishing regulatory bodies and standardized practices, the field can ensure consistent medical interpretation and integration into healthcare systems, as well as improved patient safety outcomes.

Privacy and data ownership are another challenge. Many patients fear that their genetic information could be used without their consent or used negatively by corporations to discriminate against them when seeking life insurance, healthcare, or even employment. To mitigate this, healthcare providers and institutions can implement technical, legal, and operational safeguards.

Limited insurance coverage and reimbursement after testing also limit widespread access. Although recent studies show that more insurance companies are increasing coverage, PGx healthcare advocacy by providers, patients, healthcare organizations, and government organizations still has room for improvement.

As research and technology continue to advance and evolve rapidly in healthcare, pharmacogenomics and pharmacogenetics hold exciting possibilities for the future of precision medicine. Some future opportunities include:

• Lifetime genome sequencing
• Artificial Intelligence modeling
• Integrating multi-omics

Many experts predict that sequencing patients’ entire genomes and storing them in electronic health records will soon become standard practice to guide prescribing for future medicines and healthcare therapies. This advancement would significantly reduce adverse side effects, ineffective treatments, and high medication costs.

Additionally, the union of pharmacogenomics and artificial intelligence promises faster identification and classification of drug-gene pairs through rapid genome interpretation, supporting real-time clinical decision-making and improving patient outcomes.

Finally, some researchers also predict that the future of pharmacogenomics and pharmacogenetics will extend beyond sequencing genomic data to incorporate additional layers of biological information—such as epigenetic, microbiome, nutrigenomics, and proteomic testing. 

The University of Cincinnati’s online Master of Science in Pharmacogenomics and Personalized Healthcare is the largest program of its kind in the U.S., offering students an opportunity to gain in-depth knowledge of pharmacogenomics and understand how genomics, environment, and patient-specific factors affect drug response.

Students in our program, like Brittany Konkle, gain experience working with genomic databases and applying genetic insights to real health care scenarios. Our curriculum, led by expert faculty researchers and clinicians, covers genomics, biomarkers, bioinformatics, and personalized medicine approaches, creating ample opportunities for graduates in academia, the pharmaceutical industry, research, and direct clinical care.

Most importantly, our program is designed to fit into your life and help you grow professionally without pausing your professional or personal commitments. Courses can be completed at a part-time or full-time pace, depending on what works best for you.   

Interested in starting your career in the cutting-edge field of pharmacogenomics? Or would you like to learn more about our other online pharmacy programs? Reach out to your Enrollment Services Advisor today to take the first step in advancing your career.