Doctor gesturing to prescription bottle while talking with patient in office

Pharmacogenomics for Patients

Have you ever wondered why some medications may not seem to help you as much as others?

Have you ever changed the dose or stopped taking a medication because you didn't think it worked for you or didn't like the way it made you feel?

Have you ever wanted to know how a medication may affect you before you take it?

These types of questions might be answered by pharmacogenomics (PGx), which is the study of how genes affect the body's response to medications. Emerging tools for PGx testing, also referred to as drug-gene testing, can guide your doctor to tailor your medications based on your genes. This is key to personalizing your health care.

What is PGx?

PGx is the study of how your genes may affect your body's response to, and interaction with, some prescription or over-the-counter medications.

Genes, which are inherited from your parents, carry information that determines characteristics such as eye color and blood type. Genes can also influence how you process and respond to medications.

Depending on your genetic makeup, some medications may work faster or slower, or produce more or fewer side effects.

Why is PGx important?

The results help tailor your medication based on your genes now and for future prescription needs.

What pharmacogenomic testing does

The purpose of pharmacogenomic testing is to find out if a medication is right for you. A small blood or saliva sample can help determine:

  • Whether a medication may be an effective treatment for you
  • What the best dose of a medication is for you
  • Whether you could have serious side effects from a medication

The laboratory looks for changes or variants in one or more genes that can affect your response to certain medications.

Although your genetic makeup does not change over time, it may be helpful to talk to your health care provider about having a pharmacogenomics test repeated in several years as the science and technology advances. You may need other pharmacogenomic tests if you take another medication, but laboratories can perform multiple tests from a single blood or saliva sample. Each medication is associated with a different pharmacogenomic test. Keep track of all your test results and share them with your doctor.

The need for pharmacogenomic testing is determined on an individual basis. If your pharmacogenomic test results suggest you may not have a good response to a medication, your family members may have a similar response. Mayo Clinic recommends you share this information with your family members. Your doctor can also provide recommendations for family members who may benefit from having testing.

What factors impact response to medications?

PGx testing is one tool your health care team can use to help identify the right drug for you. Many factors impact how a person responds to medication including:

  • Genetic factors
  • Other medications
  • Age
  • Sex
  • Race/ethnicity
  • Illness or organ dysfunction, especially of the kidney or liver
  • Smoking/alcohol
  • Food interactions
  • Weight-loss surgeries

When might PGx testing be recommended or considered?

There are different reasons why your health care team might order PGx testing to help guide your current or future medication use, such as:

  • To reduce the risk of serious side effects related to certain medications
  • To adjust the dose of a current medication or recommend a different medication
  • To identify a medication, or dose of a medication, with a higher chance of working for you before you take it

How much will it cost?

The cost varies depending on which test(s) is ordered. Depending on your policy and reasons for testing, some insurance companies may or may not cover pharmacogenomic testing.

Contact your insurance provider about coverage prior to testing if this is a concern. To help you determine test costs and coverage:

  • Mayo Clinic's Patient Account Services may be able to provide an estimate by phone.
  • Some insurance companies may cover pharmacogenomic testing, depending on the policy and reasons for testing.
  • Contact your insurance provider about coverage prior to testing if cost and coverage are concerns.

In addition to PGx testing costs, you will incur charges related to the visit with your doctor, and those charges may vary.

Will PGx testing affect insurance coverage?

GINA, the Genetic Information Nondiscrimination Act, prohibits medical insurance companies and employers from discriminating against individuals on the basis of genetic information, including PGx test results. This federal law does not protect you against genetic discrimination by life insurance, disability insurance or long-term care insurance companies. Some states have laws in this area. Learn more on the National Institutes of Health's Genetic Discrimination webpage.

Pharmacogenomics: Genes and Drugs

Learn about pharmacogenomics research at Mayo Clinic.

Narrator: Why do life-saving drug therapies work for some patients but not for others? And why does a medication that works well for one person cause adverse side effects in someone else?

Some of the answers may lie in our genetic makeup. That's why researchers in the Center for Individualized Medicine at Mayo Clinic are studying pharmacogenomics to better understand how inherited genetic differences affect an individual's response to drug therapy.

The Human Genome Project

Richard Weinshilboum, M.D., Mary Lou and John H. Dasburg Professor of Cancer Genomics, Director Pharmacogenomics Program: So what the genome is, is the three billion letters of the genetic code that make each of us uniquely the wonderful person we are.

We've never had the ability to do this before. And the Human Genome Project, which I think we can take great pride in, it was an international enterprise that involved Europe, Asia, and the United States, but led by the United States. Basically, set out to do what I think most of us 20 years ago thought would be impossible. I, I didn't think it would happen during my lifetime.

That is to basically give us the outline of the sequence of the human genome. Now, everybody's outline is different, because we all have about 7 million variations there that make us who we are. The genome project though, the way in which it was presented to the public, was as if it was a race to the finish line. No, no, no, no. It was a race to the starting line. Because, once we had that outline, we could then begin trying to figure out how to use that to help us understand diseases like cancer. That we really had no ability to deal with before in any meaningful way, to prevent and to treat. Number two, what made us uniquely who we are in terms of the way we respond to the medications we have.

Narrator: Mayo's researchers use knowledge gained from the Human Genome Project to analyze the genomes of thousands of individuals. An enormous task, since a single human genome contains more than three billion DNA base pairs.

Dr. Liewei Wang, and a team of talented researchers, use rapid sequencing tools to identify biomarkers that can predict the patient's response to drug treatments.

Liewei Wang, M.D., PH.D., Associate Director, Pharmacogenomics Program: Now, because we know the whole genome, the entire genome, and we have the technology to assess entire genome in a much faster and efficient way. So now we can incorporate all the genetic information from your entire genome instead of just looking at individual genes. And, by doing that, we have a complete picture and how the whole genome, may impact response to a certain drug.

Narrator: Analyzing these large complex datasets requires powerful computers that can process data and unprecedented speeds.

Dr. Wang: Eventually, we will have three billion nucleotides coming from one individual, not even meshing many other types of omics: like a polio mix, the microbiome data. So, imagine you try to integrate all of these data and you need automatic assistance and you need very sophisticated algorithm.

Narrator: To tackle this data heavy analysis, Mayo has a strategic partnership with the University of Illinois, bringing together top thinkers in technology and medicine. Supported by funding from the National Science Foundation, this Alliance is exploring better and faster ways to analyze and make sense of the pharmacogenomics team's research data.

BEAUTY Study

Breast Cancer Genome-Guided Therapy

What does this work mean for Mayo Clinic patients?

In the BEAUTY study, researchers performed DNA sequencing on breast cancer patients before and after they undergo drug therapy. Then, they compared the tumors genome, from before and after therapy, against a sequence of the patient's DNA in normal, non-cancerous tissue to match the genomic response to the drugs.

Matthew P. Goetz, M.D., Co-leader Women's Cancer Program, Professor of Oncology: I think that one of the things that we learn from the BEAUTY study was that the cancer genome indeed is complex. And, that we can identify some patients that may not derive as much benefit from standard chemotherapy.

Krishna R. Kalari, PH.D., Associate Professor, Biomedical Informatics: So what we try to do in this study is like we obtain millions of data points from these patients and then try to identify patterns using novel computation methods. And determine what are the novel pathways in each of the molecular subtypes, as well as in individual pathways what are the mutations that are altered, and those mutations that can be druggable for that particular patient.

Judy C. Boughey, M.D., Vice Chair of Research, Department of Surgery, Chair, Division of Surgery Research: As we move forward with BEAUTY2, we will be enrolling patients who have chemotherapy resistant disease, i.e., patients that complete standard chemotherapy and still have tumor left in the breast. And, making novel drugs available for those patients as part of BEAUTY2 to further try to drive to improve the outcomes of women with breast cancer.

TAILOR-PCI Study (Angioplasty Study)

Tailored Antiplatelet Initiation after Percutaneous Coronary Intervention

Narrator: In another study, Mayo researchers are performing rapid DNA analysis of patients undergoing angioplasty procedures to help cardiologists determine the right anticoagulant drug to use after the procedure.

Naveen L. Pereira, M.D., Cardiologist, Professor of Medicine: So, TAILOR-PCI is so important. We are all talking about personalized medicine and how it's going to be helpful for patients and TAILOR-PCI has now already become one of the largest genetic based clinical trials in cardiovascular diseases ever conducted.

So, what we are doing with TAILOR-PCI, is trying to prove that genetic testing could perhaps be helpful to identify those patients, one of the 30 percent of patients who could be at risk by taking Plavix (Clopidogrel), and then giving them the alternative drug with improved outcomes. Less heart attacks, less strokes, less clot in the stents, etc... Unless death perhaps, so that's what we're looking at.

RIGHT Study

Pharmacogenomic Data to Individualize Treatment

Narrator: Through the RIGHT Study, the Center for Individualized Medicine is adding data on drug-gene interactions to patients' electronic medical records.

Dr. Weinshilboum: So the RIGHT Study, which was the right drug, at the right dose, at the right time, for the right person, all that stuff... The RIGHT Study was really a pilot study to test the possibility that we can actually do that. We didn't know whether this would work.

And we picked one thousand thirteen local patients, who had their DNA in the biobank, they enthusiastically consented to participate. And what we then did was sequence all of these genes that we currently know play a role in drug response, put that information preemptively in the electronic health record. So, that when their doctor writes a prescription immediately the electronic health record, if there's going to be a problem because of their genes, sends a message to the doctor to either change the drug, lower the dose, or raise the dose, which I find astonishing.

Pharmacogenomics

Narrator: Clearly, pharmacogenomics has the potential to revolutionize the way drugs are used to treat individual patients. With high tech tools and a growing understanding of the human genome, Mayo researchers are helping to launch an era of truly, individualized medicine. Where patients can get the right drug, at the right time, in the right amount.

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Pharmacogenomics Animation

Pharmacogenomics investigates how changes in genes affect how people respond to medications. Scientists can use a patient's genetic profile to predict a drug's efficacy, guide dosage and improve patient safety.