More Than 98% of People May Carry a Genetic Variation That Could Influence Their Response to Certain Medicines

Have you ever wondered why the same medicine may work well for one person but cause side effects or provide less benefit for someone else?

There are many possible reasons. Age, kidney and liver function, other medicines, health conditions and lifestyle can all affect treatment response.

Genetics may also be one part of the explanation.

Studies indicate that more than 98% of people may carry at least one genomic variation that could influence how they respond to commonly prescribed medicines (National Human Genome Research Institute [NHGRI], 2024).

This does not mean that 98% of people are taking the wrong medicine. It means that medicine-related genetic differences are common and may become relevant when a person takes certain medicines.

What Is Pharmacogenomics?

Pharmacogenomics, or PGx, studies how variations in a person’s DNA may influence their response to medicines.

Some genes affect the enzymes and proteins responsible for activating, transporting and breaking down medicines. Because of this, a genetic variation may affect:

• how quickly the body processes a medicine;
• whether the medicine can be activated properly;
• whether a standard dose is suitable;
• whether the medicine may provide less benefit; or
• the likelihood of certain side effects.

For example, one person may process a medicine slowly, causing more of it to remain in the body. Another person may process it too quickly, reducing its effect.

However, this varies by medicine. A genetic variation that affects one medicine may have no effect on many others.

Which Medicines May Be Affected?

Pharmacogenomic information is available for selected medicines used in areas such as:

• cholesterol and cardiovascular care;
• blood pressure;
• antiplatelets and blood thinners;
• pain management;
• mental health;
• gastrointestinal conditions;
• neurology;
• infectious diseases; and
• selected cancer and immune-related treatments.

Examples include atorvastatin, clopidogrel, warfarin and tramadol. Each medicine is linked to different genes and levels of scientific evidence.

This is important because not every medicine in a pharmacogenomic report has the same level of clinical actionability. Some results may support a dose adjustment or alternative medicine, while others may only indicate the need for monitoring or provide additional information.

What Is pro.Genome Pharmacogenomics?

pro.Genome Pharmacogenomics is a DNA-based test that provides information about how a person’s genetic variations may relate to selected medicines.

The report covers information relating to 287 medications across multiple treatment areas. Findings may be grouped into categories such as:

• follow standard dosing;
• consider closer monitoring;
• consider a different starting dose; or
• consider an alternative medicine.

These categories are intended to support discussion with a qualified healthcare professional. They are not instructions for patients to change medicines on their own.

Who May Find It Useful?

Pharmacogenomic testing may be worth discussing for people who:

• take several long-term medicines;
• have experienced significant or unexplained side effects;
• have had limited benefit from certain medicines;
• require repeated dose adjustments;
• have a complex medication history; or
• want information that may support future medication decisions.

Because inherited DNA generally does not change, the results may remain useful when relevant medicines are considered later in life.

What Are the Limitations?

Pharmacogenomics is only one part of medication decision-making.

Medicine response can also be influenced by age, body weight, kidney and liver function, other medicines, diet, alcohol, smoking, adherence and the condition being treated.

Testing also cannot:

• predict every side effect;
• guarantee that a medicine will work;
• identify every possible genetic variation; or
• replace a doctor’s or pharmacist’s clinical judgement.

A genetic variation does not automatically mean that a medicine is unsuitable. In some cases, closer monitoring may be enough.

The Key Message

The main message behind the “more than 98%” statistic is simple:

The same medicine may not affect every person in exactly the same way.

Pharmacogenomics may help explain part of that difference and provide additional information for medication selection, dosing and monitoring.

However, no medicine should be stopped, reduced, increased or changed based only on a genetic report.

Speak with an Alpro pharmacist or qualified healthcare professional to learn more about pro.Genome Pharmacogenomics and whether it may be relevant to your medication history.

This article is intended for general educational purposes only and does not replace medical advice, diagnosis or treatment from a qualified healthcare professional.

References

Chan, S. H., et al. (2022). Analysis of clinically relevant variants from ancestrally diverse Asian genomes. Nature Communications, 13, Article 6694. https://doi.org/10.1038/s41467-022-34116-9

National Human Genome Research Institute. (2024, December 24). Pharmacogenomics fact sheet. https://www.genome.gov/about-genomics/educational-resources/fact-sheets/pharmacogenomics

Yu, M. H. C., et al. (2021). Actionable pharmacogenetic variants in Hong Kong Chinese exome sequencing data and projected prescription impact in the Hong Kong population. PLOS Genetics, 17(2), e1009323. https://doi.org/10.1371/journal.pgen.1009323