With drug response testing, a cheek swab extracting cells containing your DNA is sent to a laboratory where it is analyzed to determine how you metabolize medications. The results are shared with your health care provider, who can then select the safest and most effective drug for you.

"Drug response testing is an upfront investment that Vandenhurk believes will result in long-term savings to companies offering health plans."

"DNA tests support the growing trend of personalized medicine, which allows clinicians to prescribe medications tailored to the genetic makeup of their patients, thus avoiding terrible side effects, not to mention the waste of time and money spent on a drug that doesn’t even work,” says Dr. Zayna Khayat, the lead of MaRS Health and Director of MaRS EXCITE in Toronto.

Many commonly prescribed medications (such as the heart medication Plavix, which cannot be metabolized by up to 30 percent of Southeast Asians) are not effective or cause severe side effects in some people, points out Dr. Ruslan Dorfman, CEO of the pharmacogenetic testing company GeneYouIn, which operates out of the MaRS Centre. Dr. Dorfman notes that genetic testing is especially helpful to patients suffering from conditions that are not easily treatable. 

For instance, drug response testing can help physicians better understand patients suffering from chronic pain who have been on high doses of opioids such as OxyContin for a long time but have not experienced a reduction in pain. In cases like these, when a doctor may wonder whether a patient is, in fact, addicted to the medication, “the science may actually prove that this person has an issue metabolizing the drug, and then a physician can recommend an alternative treatment,” says Dr. Dorfman.

Drug response testing also empowers patients, allowing them to better control their medical condition. Patients who know upfront that they are being prescribed the right medication at the right dose and that they will have less adverse drug reactions, if any, are more likely to take their prescribed medication on a regular basis, points out Dr. Dorfman. Customers report more meaningful conversations with their physicians and pharmacists and less distress if they experience side effects, because they know ahead of time what is to be expected.

Drug response testing in the workplace

In the workplace, companies that provide drug response testing as part of their health benefits could see less absenteeism and lower disability costs, according to Maria Vandenhurk, COO of the disability management provider Banyan Work Health Solutions.

“By and large, a lot of drug regimens are not working,” Vandenhurk says. Many workers on prolonged disability “struggle with their medication — they have side effects, they don’t like taking the medication” and see no improvement, she says. Vandenhurk believes that workers would be more likely to adhere to treatment if results were based on clinical evidence, evidence that could steer them toward certain dosages or drugs and away from others.

Drug response testing is an upfront investment that Vandenhurk believes will result in long-term savings to companies offering health plans. For example, each employee who receives appropriate therapy for depression can save employers more than an estimated $5,000 to $10,000 per year on wage replacement, sick leave and prescription drugs costs, according to a 2013 study in Translational Psychiatry.

The study also points out that almost two-thirds of patients prescribed anti-depressants fail to respond to the initial medication trial, and 75 percent to subsequent trials. “A drug is prescribed and gets abandoned, and then another drug is prescribed and it gets abandoned, and, meanwhile, leave duration is the silent cost in the background,” says Vandenhurk.