Existing Drug May Help Prevent Opioid Relapse, Study Finds

Researchers at University of Iowa discover acetazolamide, a drug used for other conditions, could target brain changes that contribute to opioid use disorder.

Published on Feb. 13, 2026

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Researchers at the University of Iowa have found that the existing drug acetazolamide, currently used to treat glaucoma, altitude sickness, and seizures, may also have potential for preventing relapse in opioid use disorder. The drug works by blocking the activity of a brain enzyme called carbonic anhydrase 4, which appears to regulate how neurons in the brain's reward center respond to drugs like opioids and cocaine. By inhibiting this enzyme, the researchers found they could prevent some of the harmful brain changes and drug-seeking behaviors that occur after withdrawal.

Why it matters

The opioid crisis remains a major public health problem, with overdose deaths still at high levels. Current medications for opioid use disorder mostly target the opioid receptors, but do not address the deeper brain changes that make people vulnerable to relapse. Finding new treatment approaches that work differently, like targeting the brain's reward system, could open the door to more effective therapies to help people stay in recovery.

The details

The UI researchers, led by John Wemmie, focused on acetazolamide (AZD) because it blocks the activity of the carbonic anhydrase 4 (CA4) enzyme. Their previous work had shown that inhibiting CA4 in the brain's reward center reduced drug-seeking behavior and relapse in mice after cocaine withdrawal. In the new study, they found that disrupting CA4 genetically or with a single dose of AZD also prevented adverse changes in the brain and behavior after withdrawal from the opioid oxycodone in mice. Blocking CA4 reduced the strengthening of drug-related synaptic connections and the desire to seek the drug, suggesting AZD might help prevent relapse in people recovering from opioid use disorder.

  • The new study was recently published in Neuropsychopharmacology.

The players

John Wemmie

A professor of psychiatry in the UI Carver College of Medicine and the lead researcher on the study.

University of Iowa Health Care

The institution where the research was conducted.

Acetazolamide (AZD)

An existing drug currently used to treat glaucoma, altitude sickness, and seizures that the researchers found may also have potential for preventing relapse in opioid use disorder.

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What they’re saying

“What makes this approach promising is that it works in a completely different way from current treatments. Instead of targeting opioid receptors, AZD targets a different pathway involved in drug-induced synaptic changes and drug-seeking behavior. This could open the door to new therapies that help people stay in recovery by addressing the brain's long-term response to drug use.”

— John Wemmie, Professor of Psychiatry (Mirage News)

What’s next

The researchers plan to further study acetazolamide and its potential for treating opioid use disorder, with the goal of eventually testing it in human clinical trials.

The takeaway

This research highlights a promising new approach to addressing the opioid crisis by targeting the brain's reward system, rather than just the opioid receptors. If successful, this could lead to more effective treatments to help people recovering from opioid addiction stay in recovery and avoid relapse.