AltaPointe Health Study Finds Low-Dose Ketamine Helps Fentanyl Users Start Buprenorphine Without Severe Withdrawal

MOBILE, Ala., Feb. 20, 2026 /PRNewswire/ -- Drug overdoses caused an estimated 73,000 U.S. deaths last year, with the synthetic opioid fentanyl causing the majority of fatal overdoses. 

Buprenorphine, a medication for treating opioid-use disorder, is effective and saves lives, but people often avoid it for fear of painful opioid withdrawal symptoms that can occur when starting the medication. 

This is particularly true among fentanyl-dependent individuals, many of whom report that buprenorphine initially makes their symptoms worse before abating. Withdrawal symptoms of muscle aches, vomiting, diarrhea, sweating, chills, restlessness and anxiety can increase in severity for up to five days.

Findings published Feb. 11 in the journal Addiction Science and Clinical Practice showed that a new strategy of using an extremely low intramuscular dose of the anesthetic ketamine before starting buprenorphine led to a rapid, large reduction of fentanyl withdrawal symptoms in nearly all patients, without any side effects. Most patients could then immediately start buprenorphine without a return of withdrawal symptoms.

"It has been a challenge helping individuals dependent on opioids in the fentanyl era, and this simple, inexpensive and highly effective treatment strategy has a lot of promise in helping people transition to buprenorphine safely and comfortably. The hope is that this will be another opportunity to make a dent in the ongoing opioid overdose epidemic," said first author, Dr. Luke Engeriser, deputy chief medical officer for AltaPointe Health and associate professor at the University of South Alabama.

Dr. Engeriser designed the study which followed 50 patients experiencing fentanyl withdrawal at AltaPointe's 24-hour Behavioral Health Crisis Center in Mobile, Alabama. Over half of the patients were completely free of withdrawal symptoms within an hour of starting the ketamine-assisted buprenorphine therapy, and the average length of stay at the facility dropped from 66 hours to seven hours. Almost all patients were stable enough for discharge from the crisis center within hours after the first buprenorphine dose. The ketamine treatment costs 44 cents per patient. 

In emergency departments, a high dose of ketamine, causing intense drowsiness, has been shown to reverse withdrawal symptoms after starting buprenorphine. This study was the first demonstration that a low dose of ketamine could both relieve fentanyl withdrawal and prevent renewed symptoms after starting buprenorphine. 

The researchers think this strategy could be adapted for use in many settings where buprenorphine treatment is offered, including inpatient, emergency department, residential treatment, withdrawal management, crisis center, outpatient, prison/jail or mobile clinics, and warrants further study in these settings. Importantly, since ketamine is a controlled substance, injection by a healthcare provider is safer than self-administration as it avoids the risk of misuse by patients.

"I have seen the impact this protocol has had in quickly and relatively comfortably transitioning patients from dangerous use patterns onto a path to recovery and stability. It has been very gratifying to provide such a benefit to the person in front of me while contributing to a shift in how many others receive care," said Dr. Evan Chavers, a co-author of the study and chief resident of the University of South Alabama psychiatry residency.

This report of the use of sub-dissociative dose ketamine to block withdrawal symptoms affirms and greatly strengthens findings from a previously published pilot study from the senior author of this week's report, Dr. Lucinda Grande, a primary care doctor in Lacey, Washington and a clinical associate professor of family medicine at the University of Washington School of Medicine, who specializes in chronic pain and addiction treatment.

The paper is available at: https://rdcu.be/e3Brj

SOURCE AltaPointe Health Systems