UC researcher examines genetic role in addiction

In one of the first studies of its kind, a University of Cincinnati researcher is using a grant from the Ohio attorney general’s office to research the pharmacogenomics of opioid addiction.

The grant was awarded to Caroline Freiermuth, MD, associate professor in the Department of Emergency Medicine at the UC College of Medicine, the principal investigator for the study. The initial year will be supported with $1.63 million from the attorney general’s office, secured through money collected from pharmaceutical companies involved in opioid lawsuits.

Pharmacogenomics, a relatively new field, is the study of how genes affect a person's response to drugs.

“We want to find out if there are certain genetic markers that affect a person’s risk for taking opioids, using them the wrong way or becoming addicted,” says Freiermuth.

The study is taking place both at UC and Ohio State University, an approach which Freiermuth says will catch a broader swath of people. She says there are two goals for the research. The first is to identify any genetic markers associated with opioid use disorder (OUD), and the second is to get a cross-sectional snapshot of how many patients in the emergency department actually have OUD, as this is likely under-recognized and underdiagnosed.

“We look to enroll both patients who don’t have opioid use disorder as well as patients who do, because we want to be able to compare their genetic markers,” Freiermuth says. “Patients will get an oral swab that gets put inside their cheek, and those swabs will be sent off for genetic testing looking for 180 single nucleotide polymorphisms (SNP), which are individual genetic markers.”

Freiermuth says 120 of the SNPs are genetic markers that are suspected to have something to do with addiction. Some are dopamine pathways, others have been shown or theorized to be associated with alcohol addiction or tobacco addiction. Sixty of the SNPs are those dealing with opioid metabolism specifically, so the researchers want to see if those are different among people who have OUD compared to those who don’t.

After a delay due to the COVID-19 pandemic, the first patients were enrolled at UC in May and the 100th patient signed up in early September. Freiermuth has been impressed by the enthusiasm by patients in the emergency department to take part in the study.

“About 40% of patients who are approached agree to participate in this study, which is pretty impressive for any study run in the ED where we have this very chaotic environment, patients are coming and leaving their room for various tests,” she says. “They’re there because they’re in pain or they have some other complaint that they sought care for, and here we are interrupting their day asking them to participate in this research that won’t directly benefit them but has the potential to benefit others. People have jumped at the chance, it is very inspiring to watch. People have no experience with OUD but have just seen everything on the news want to participate to help people.”

Daniel Adams, 30, of Cincinnati, recently joined the study, saying he wants to help people avoid being in his position.

“I want to be involved in any type of effort that has to do with helping other people,” says Adams. “Is this a genetic thing, and if it is, is there a way to stop it at a younger age? I have an 11-year-old daughter and 10-year-old son and maybe they might end up on drugs. My dad was an alcoholic and he liked doing heroin and cocaine and I have a drinking problem and I do heroin and cocaine. I did exactly what my dad did. I believe it is genetic. My son has red hair just like me. Genetics can be passed down through looks, eyes, hair, why can’t it be passed down through actions and emotions?”

The goal is to enroll up to 1,500 patients over the next year or so. At UC, Mike Lyons, MD, associate professor in the Department of Emergency Medicine, and Jennifer Brown, associate professor in the Department of Psychiatry and Behavioral Neuroscience, will be co-investigators of the study.

“I think it’s exciting,” says Freiermuth. “It’s pretty new and novel. Nobody has done much with the genetic aspect of OUD. There has been a focus to provide treatment, both with medicated-assisted treatment and taking care of all the complications that arise from OUD, and there aren’t many people looking at preventing [it].”

Lead image/istock.