A medication that has long been used to treat glaucoma, altitude sickness, and certain types of seizures may also help people recovering from opioid addiction avoid relapse, according to new research from the University of Iowa Health Care.
The drug, called acetazolamide, has been studied for its effects on the brain systems involved in drug cravings and relapse.
The findings, published in the journal Neuropsychopharmacology, suggest that this existing medication could offer a new approach to treating opioid use disorder.
Unlike current treatments, which mainly target the same brain receptors affected by opioids, acetazolamide works through a completely different pathway.
Opioid addiction remains a serious public health crisis, with high rates of overdose deaths and relapse.
Many people in recovery experience intense cravings and are at risk of returning to drug use, especially during withdrawal.
While approved medications can ease withdrawal symptoms and reduce cravings, they do not fully address the long-term changes that drug use causes in the brain.
The Iowa research team, led by psychiatrist Dr. John Wemmie, focused on an enzyme in the brain called carbonic anhydrase 4.
This enzyme influences how brain cells communicate in areas linked to reward and motivation, particularly a region known as the nucleus accumbens. This area plays a major role in drug-seeking behavior.
In earlier studies, the scientists found that blocking this enzyme in mice reduced drug-seeking behavior after withdrawal from cocaine.
In the new study, they explored whether the same approach could help prevent relapse related to opioids.
They discovered that disrupting the enzyme’s activity—either genetically or with a single dose of acetazolamide—reduced harmful brain changes caused by withdrawal from oxycodone, a commonly misused opioid.
The drug appears to work by boosting the activity of certain proteins that help regulate communication between brain cells. When these proteins function properly, neurons become less sensitive to the changes caused by addictive drugs. This may reduce the urge to seek out drugs after a period of abstinence.
Importantly, acetazolamide is already approved for human use and has a well-known safety record, which could make it easier to test in clinical trials for addiction treatment.
Researchers believe it might be used alongside existing therapies to help people maintain recovery by targeting the brain’s long-term response to drug use, not just withdrawal symptoms.
Although the results so far come from animal studies, the findings open the door to a new way of thinking about addiction treatment. Instead of focusing only on opioid receptors, future therapies might target the deeper brain changes that drive relapse.
Scientists hope that repurposing an established drug could speed up the development of new treatments for opioid use disorder and possibly other substance addictions.
If further studies confirm its effectiveness in people, this approach could provide new hope for individuals struggling to stay drug-free and support long-term recovery.
