Study ‘ignites’ link between genes and drug response

July 29, 2019

Vanderbilt University Medical Center is leading a national study to determine whether genetic testing can help physicians choose the best drugs for their patients to relieve pain and depression.

The study is part of the second phase of investigations known as the IGNITE (Implementing GeNomIc pracTicE) network, established in 2013 by the National Institutes of Health to help incorporate genomic information into clinical care.

How well patients respond to SSRI antidepressant medications or pain-relieving drugs such as codeine, tramadol, and hydrocodone depends in part on whether they have genetic variants encoding the enzymes that metabolize or break down the drugs before they have a chance to work.

Testing for the presence of these genes could help physicians predict in advance which drugs will be most effective in individual patients. Yet this approach, especially in treating depression and in pain control, has not yet been validated by large clinical trials.

That’s what ADOPT-PGx (A Depression and Opioid Pragmatic Trial in Pharmacogenomics) is designed to do, said Josh Peterson, MD, MPH, associate professor of Biomedical Informatics and Medicine in the Vanderbilt University School of Medicine.

“We really need to build the evidence base for this kind of genetic testing where you deliver results and advice just-in-time at the point of prescribing, from a source that clinicians can trust, and so it impacts what kinds of decisions they’re making,” Peterson said.

Peterson is co-directing the study with Joshua Denny, MD, MS, professor of Biomedical Informatics and Medicine and director of the VUMC Center for Precision Medicine.

Patients with acute post-surgical pain, chronic pain, and moderate depression will be enrolled in the study. Each participant is randomly assigned to one of two different groups.

In one group, physicians will be given their patients’ results for genes that encode drug-metabolizing enzymes to help guide their prescribing decisions, while in the other, or control group, physicians won’t receive that information until after the study is completed.

How well patients in each group respond to the medications they’re prescribed will then be compared. The goal is to see how well the delivery of these tests “plays out” in routine care of pain and depression, Peterson said.

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