A vital piece of information that might be overlooked by your physician when prescribing medication lies within your DNA.
Research released on Wednesday in Science Translational Medicine indicates that nearly 25% of study participants received prescriptions for medications that might have necessitated an alternative drug or dosage due to their genetic makeup.
Conducted by scientists at the University of Pittsburgh, the study focused on 16 genes that influence the body’s response to various medications.
The analysis involved DNA samples from 98,590 individuals enrolled in the National Institutes of Health’s All of Us Research Program, which were correlated with available medical records.
Every participant had at least one significant genetic variation that could influence their response to specific medications, with the average participant possessing nine variations. Among those who had both genetic and clinical data, 24.4% had been prescribed at least one medication that guidelines suggest should have been substituted with a different drug or adjusted in dosage based on their genetic profile.
Nonetheless, the study did not assess whether patients faced adverse effects or if their medications were less effective due to their genetic characteristics.
Dr. Philip Empey, the study’s senior author and an associate professor at the University of Pittsburgh’s pharmacy school, emphasized that understanding a patient’s genetic profile could minimize the trial-and-error process involved in prescribing medications.
“Anything we can do to enhance our initial predictions about the most suitable medications and appropriate dosages will significantly reduce the trial and error involved,” he stated.
A pharmacist organizes medications at a pharmacy in Vancouver in October 2022. Genetic variations can influence how patients react to certain drugs, potentially necessitating adjustments in dosage or alternative prescriptions. (Darryl Dyck/The Canadian Press)
Choosing the right medication
Among the frequently prescribed medications for participants whose genetic profiles suggested potential treatment alterations were omeprazole and pantoprazole for acid reflux, as well as atorvastatin for cholesterol management.
Empey pointed out that certain genetic variations may elevate the risk of muscle-related issues when patients are prescribed statins like atorvastatin, which are intended to lower the risk of heart attacks or strokes.
This insight could assist healthcare providers in selecting alternative medications or adjusting treatment plans.
“It enables clinicians to make more informed choices, like considering not to prescribe that specific cholesterol medication, starting with a lower dose, determining a maximum dosage, or monitoring for particular side effects more closely,” Empey explained.
For certain drugs, the implications can be even more severe.
For instance, specialists consulted by CBC News indicated that genetic testing can identify patients who may not respond effectively to clopidogrel (Plavix), a medication utilized to avert blood clots after cardiac stenting, allowing healthcare providers to opt for alternative treatments.
Dr. James Kennedy leads the Tanenbaum Centre for Pharmacogenetics at Toronto’s Centre for Addiction and Mental Health. He notes that while genetic testing can assist in medication selection, other factors like diet, lifestyle, and existing medications must also be taken into account. (CBC)
A guide, not an assurance
Dr. James Kennedy remarked that the findings of this study were not unexpected, but he was particularly impressed by the genetic diversity and representation of individuals of African descent.
Kennedy mentioned that his team has conducted genetic testing for about 11,000 patients, many of whom had previously tried two to three antidepressants without achieving satisfactory results.
He noted that roughly 8 to 10 percent of individuals metabolize certain common antidepressants at an unusually slow rate, which can lead to an accumulation of the medication and potentially cause side effects.
Kennedy highlighted that genetic testing is particularly beneficial for patients who have faced challenges with multiple medications.
However, he pointed out that DNA testing alone cannot predict an individual’s response to a specific medication. Factors such as other prescriptions, smoking habits, and dietary choices are also crucial.
“We say, ‘Here’s your genetic blueprint, here are some tendencies you might have, and let’s discuss all the other considerations before making a conclusive decision,'” he explained.
A 2023 European clinical trial referenced in the study found that genetic testing prior to prescribing certain medications decreased the likelihood of adverse drug reactions. Nevertheless, implementing routine testing in Canada poses challenges.
A researcher at the University of Calgary demonstrates a diagnostic kit used for identifying genetic variations in February 2024. While such testing could enhance the customization of medications for patients, cost and logistical challenges have hindered its widespread implementation in Canada. (Jeff McIntosh/The Canadian Press)
Barriers to widespread genetic testing in Canada
Dr. Jacob Udell, a cardiologist in Toronto, described the study as impressive, particularly in terms of the genetic diversity of its subjects. However, he noted that few healthcare providers in Canada or the U.S. routinely evaluate patients for genetic variations that may impact medication metabolism.
“It’s certainly not something that frontline clinicians typically consider,” he remarked.
Udell explained that for many conditions, physicians can prescribe a medication, observe the patient’s response, and make necessary adjustments without significant risks. This method can be more practical than routinely screening patients for genetic variations.
He also questioned the priority of widespread testing in light of the ongoing struggle within Canada’s healthcare system to provide fundamental services.
“We’re focused on ensuring everyone has access to a family doctor,” he stated.
In addition to the testing costs, Udell mentioned that healthcare providers would require access to genetic test results and the knowledge to interpret them accurately.
Empey concurred that making genetic testing a standard procedure would necessitate substantial investments in training, infrastructure, and new systems for sharing results among healthcare professionals.
“The scientific evidence is robust for numerous medications. The considerations surrounding implementation are more economic, procedural, and educational,” he stated.
For the time being, Empey suggested that patients inquire with their doctors or pharmacists about the potential benefits of genetic testing and share any relevant results with them.
Udell cautioned that private testing may become more prevalent for those who can afford it, “but this approach does not assist those who cannot cover the costs of testing.”
Tag: rewrite-pending