MADISON – University of Wisconsin-Madison scientists have discovered that a majority of people they tested who were taking opioid painkillers for chronic back pain produced antibodies against the drugs that may contribute to some of the negative side effects of long-term opioid use.
The findings add to a growing understanding of how the immune system can recognize drugs and influence their effects in the body, which may ultimately support the production and delivery of a vaccine that reduces the harm of opioid abuse.
Cody Wenthur, a professor in the UW-Madison School of Pharmacy, led the work with collaborators at the Scripps Research Institute and Scripps Health in San Diego. Wenthur lab postdoctoral researcher Jillian Kyzer announced the team’s findings Aug. 17 at the American Chemical Society Fall 2020 virtual meeting.
The researchers discovered antibodies against protein-bound opioids in 10 of 19 patients who took opioids to treat chronic lower back pain. Those who took higher doses of opioids had a stronger antibody response. A control group of three patients who did not take opioids for their back pain had only very low levels of anti-opioid antibodies.
For this initial study, Wenthur’s team could only identify three patients with chronic pain who had not previously taken opioids, even after a months-long radio and print recruiting campaign. This challenge was an indication of the ubiquity of these drugs, despite evidence that they are riskier options than non-opioid painkillers for treating chronic pain.
“Opioid use disorder and opioid overdoses continue to be a major epidemic in this country,” says Wenthur. “A relatively new therapeutic approach entering clinical trials is what in shorthand we call an opioid vaccine, where the immune system generates a response against the drugs. But for this approach to be successful, we need to identify the people who would benefit from that approach.”