Pharmacogenomics: New tests help determine which medications are right for you

Have you ever wondered why you might have side effects when taking a medication but another person doesn’t experience any? Or why a medication might work well for a friend but you don’t respond to it?

It turns out, a person’s DNA can affect how they respond to medication. We are all unique, which means we all react differently.

Pharmacogenomics is the study of a person’s DNA and understanding how small changes may affect how they respond to medication. The term was coined in 1955, but its application into clinical care is relatively new. Here are answers to some of the most commonly asked questions we get from patients:

How does a person’s DNA affect their reaction to medication?

There are three main ways a person’s DNA may affect their reaction to medication. All have to do with how the drug is activated by the body:

  • Drug metabolism – This can work in two ways: activation and breakdown. If your body is unable to activate a medication, you won’t get the benefit from it. If your body activates it too well, you’ll get side effects. On the flip side, if your body breaks down a medication too quickly, you won’t get any benefit. But if your body is unable to break down a medication, you’ll end up with side effects.
  • Drug transporters – Medications move through your body via drug transporters. The way your body’s drug transporters work affects how much of the drug gets to parts of your body, which changes the effectiveness or determines if side effects will occur.
  • Drug receptors – Once the drug is where it needs to go in your body, it needs to bind to receptors. It’s like fitting a key into a lock. Genetic changes can affect your receptors and you might end up with receptors that don’t fit the drug or don’t fit it as closely as needed, which can change effectiveness.

What medications may be affected by a person’s DNA?

Medications linked to pharmacogenomics make up about 20 percent of medications that are prescribed. A few common ones include:

  • Antidepressants, such as Zoloft or Celexa
  • Blood thinners, such as Plavix
  • Pain medications, such as Codeine and Tramadol
  • High cholesterol medications, such as Zocor

Who qualifies for pharmacogenomics?

At NorthShore University HealthSystem, we believe this information is valuable for everyone. That’s why every NorthShore patient can have their physician order pharmacogenomics testing. It’s a simple blood draw in a lab or you can come into our clinic at the Neaman Center for Personalized Medicine. Within two weeks you’ll get your results. These results will be used throughout the course of your life as you are prescribed medication.

We know when we do this type of testing for patients, we are likely to find something. If you’re over the age of 45, there’s a 50 percent chance you’ll be prescribed a medication that’s linked to pharmacogenomics. Everyone has variations on how they’ll respond to these medications but understanding your DNA can help you avoid side effects or having to try multiple types of medication to find one that’s effective for you.

How does pharmacogenomics improve patient care?

One of the top benefits is that it reduces trial and error when prescribing medication. For example, a patient might normally have 10 medication options. We can cut that down to three or four, making it more likely we’ll find an effective option faster.

This also helps with patients adhering to a treatment plan. When a medication works, patients are more likely to stick with and take it as prescribed by their doctor.

Patients also feel more empowered in decision-making because they have scientific data at their fingertips. They feel like they are part of the process and more invested in their care and treatment.

How is NorthShore University HealthSystem incorporating pharmacogenomics into patient care?

We started using pharmacogenomics at NorthShore in 2014. In 2015, we started the longest-running multidisciplinary pharmacogenomics clinic in the country.

Through mid-2022, we’ve tested more than 20,000 people, which is the largest population tested through clinical multigene pharmacogenomics. We’ve tested people across the spectrum and we use this information more than anyone else in the country.

It’s a priority for us to have the system-wide integration. When we started it, there weren’t many health organizations implementing clinical pharmacogenomics. Over the years, we’ve built our system so no matter where you get care in the NorthShore system, your pharmacogenomic data is in your records for your provider. From your primary care doctor’s office to our emergency rooms, your provider has the information that’s needed to select the right medication for you.

We are on the cutting edge of this type of medicine and we do it because we want to provide the best possible care for our patients. At NorthShore, we believe all medicine should be personalized medicine – care that truly fits each patient.

If you’re interested in learning more about pharmacogenomics, talk to a NorthShore primary care provider or reach out to the Neaman Center for Personalized Medicine at 847-570-GENE (4363) .