In the face of the alarming number of opioid-related deaths in the U.S., there have been national efforts to increase emergency clinician prescribing of buprenorphine, a medication used to treat opioid use disorder. In a new study published in JAMA, UCLA Health researchers report on the extent and success rate of such efforts in California.

Opioid-related emergency department (ED) visits, hospitalisations, and deaths have increased markedly since 1999, and the growing number of cases was declared a public health emergency in 2024. Combined psychotherapy and medication, either methadone, buprenorphine, or naltrexone, is the standard treatment for this condition. Buprenorphine works by binding to the opioid receptors on the cell's surface in the brain; it reduces cravings and withdrawal symptoms but does not produce the euphoric feeling that other opioid drugs induce. BRIDGE, an organization dedicated to improving access to substance use disorder treatment, started a California-wide initiative in 2019 for EDs to begin prescribing buprenorphine for opioid use disorder with linkage to addiction treatment.

"For a lot of people who use opioids, the emergency department might be the only touch point they have with the healthcare system, so it's a huge window of opportunity to make a difference," said Dr. Annette Dekker, an assistant professor in the Department of Emergency Medicine at UCLA and first author of the study. "We start these patients on buprenorphine, but we have no way of knowing if they continue on that medication or not, so the study was driven from an interest in understanding patients' trajectories after initiation in the ED."

To conduct the study, the researchers analysed data on buprenorphine prescriptions in the California Controlled Substance Utilisation Review and Evaluation System from 2017-2022.

The study found that the number of emergency medicine clinicians who prescribed buprenorphine rose from 2% to 16% of all California buprenorphine prescribers and buprenorphine initiation prescriptions from the ED increased from 0.1% to 5%. "We're seeing this huge shift of prescriptions over five years -- the efforts are working," Dekker said. The study also found that at least one in three patients is filling a second buprenorphine prescription within 40 days of the ED initiation prescription and one in nine patients is receiving continuous buprenorphine prescriptions within a year of an ED initiation prescription.

"I'm very encouraged by the results," Dekker said. "Nevertheless, the percentage of patients linked to continuous treatment is going down, which suggests to me that we need to keep investing in these connections to outpatient care from the emergency department, such as BRIDGE, and outpatient treatment capacity which can provide continuous treatment."