At St. Clair Hospital, Pharmacogenomics is Improving the Way Doctors Prescribe Medications
By Nancy Kennedy

St. Clair Hospital has teamed with Mayo Clinic in a new, cutting-edge program that will enable St. Clair physicians to choose the most effective and safest medications for their patients by utilizing each patient’s unique genetic information. Known as pharmacogenomics, or PGx for short, the program combines pharmacology, medicine and genetic science, (genomics), to study how a person’s genes affect their response to medication. The goal of the PGx program is to help physicians select the drugs and doses that are best for each individual patient.

Although prescribing medications has often been a “one size fits all” proposition, the reality is that not everyone has the same response to the same medication. We now know that people respond to many medications according to their genetic makeup. Genetic variations determine how quickly or slowly one metabolizes medications, for example; if your genes make you a fast metabolizer, your body may process a drug before it has had a chance to work. You’re taking the medication as prescribed, but you’re not getting the result that you and your doctor had hoped for and expected. PGx testing can determine how your body is likely to respond to a specific medication and whether or not it will be effective as a treatment for your condition. It can also help physicians determine the most accurate dosage for you, and it can determine whether or not a medication is safe for you or likely to cause adverse effects.

“PGx testing helps doctors tailor prescriptions more precisely,” explains Karl E. Bushman, M.D., an internist with St. Clair Medical Services and the lead physician on St. Clair’s multidisciplinary team that has been working with Mayo Clinic’s Center for Individualized Medicine to develop the PGx program. (St. Clair is a member of the Mayo Clinic Care Network and, therefore, enjoys a clinical collaboration with Mayo Clinic.) “For some patients, the standard dose of a medication may not work, or it may cause an adverse reaction, and this can be due to your genes. PGx looks specifically at the genes that control liver enzymes; the liver metabolizes, or breaks down, the medications we take. PGx enables us to look at certain common medications to determine how your body will metabolize them. This information helps the doctor determine what will work best for the individual — the usual dose, a higher dose, or a lower dose? Your DNA can affect whether or not a drug will be beneficial for you.”

Pharmacogenomics is one aspect of precision medicine or individualized medicine, an emerging medical discipline that uses the patient’s unique genetic profile to personalize and customize their care and treatment with unprecedented accuracy. This new approach is believed by many experts to eventually become the standard of care in the future, optimizing treatment and outcomes in many specialties. Currently, PGx testing is available for commonly prescribed cardiac medications, blood thinners, gastric reflux medications, pain relievers and psychotropic drugs, including many anti-depressants.

PGx testing requires a blood sample, taken at one of St. Clair’s Outpatient Centers, a St. Clair Medical Services office, or the Hospital. The sample is sent to Mayo Clinic and analyzed. A thorough genetic report is prepared for the individual patient and is forwarded to one of St. Clair’s clinical pharmacy specialists, who interpret the results for the physician and patient. The decisions about changes in medications are made mutually by the physician and patient.

“PGx testing is a powerful new tool that enables doctors to better understand your unique response to the medications you are taking, giving you the greatest possible clinical benefits, while also protecting you from adverse reactions,” says Kaitlin Shotsberger, RN, MSN, CNL, Executive Director of Quality and Care Management at St. Clair. “With PGx testing, we will transition from a ‘one size fits all’ traditional approach to prescribing to a highly individualized one that takes one’s genetic makeup into consideration. It’s especially helpful for patients with multiple medical conditions and complex ones.”

PGx testing will continue to advance and more drugs will be added to the testing panels. Once you have had a genetic profile created, it is yours and it can be shared with other physicians and specialists in the future as needed. Patients should always tell their doctors if they are not getting the expected result from a medication, or if they are experiencing bothersome side effects, Dr. Bushman advises. “Never make medication changes on your own. Talk to your doctor.”

For more information about PGx testing at St. Clair, please email mayo.inquiries@stclair.org.

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