Introduction: With the current opioid crisis in Canada, presentations of acute opioid withdrawal (AOW) to emergency departments (ED) are increasing. Undertreated symptoms may result in relapse, overdose and death. Buprenorphine/naloxone (bup/nal) is a partial opioid agonist/antagonist used to mitigate symptoms of AOW, approved by Health Canad in 2007 for opioid use disorder. It is superior to clonidine, and increases follow up with addiction treatment programs when initiated in the ED. Nevertheless, in our inner-city ED in 2014, bup/nal was rarely prescribed. We aimed to increase ED physician prescribing of bup/nal for AOW by 50% over a 26-month period. Methods: Commencing in 2014, an interprofessional team of ED physicians, nurses (RN), pharmacists and QI specialists collaborated to improve the care of patients with AOW. PDSA cycles included: (1) needs assessment of emergency physicians knowledge and practices in 2014; (2) Grand Rounds and a web based information sheet in 2015; (3) ED stocking of bup/nal; (4) convenience order set to standardize AOW management; (5) Grand Rounds in 2016 and (6) peer-coaching for RNs, including case-based discussions and pocket card cognitive aids. The outcome was the number of times bup/nal was prescribed per month by ED physicians between Sept, 2015 and Oct, 2017. Data included the prescriber and use of order set as the process measure. The balancing measure was the number of patients referred to the Addiction Medicine Team who subsequently received bup/nal. Results: Bup/nal was prescribed by ED physicians 70 times, and 14 times by the Addiction Medicine Team. With each PDSA cycle, there was an increase in prescribing, with no significant shifts or trends. By all physicians, the median number of prescriptions per month was 3, and increased from 2 to 4 prescriptions/month after nursing education. There was a smaller increase in the median from 2 to 3 prescriptions/month by ED physicians alone. The order set was used 97% of the time. Conclusion: Bup/nal is safe, effective, and increases follow up with addiction programs for comprehensive assessment and treatment planning. We met our goal of increasing bup/nal prescribing in the ED for AOW by 50%. Moreover, prescribing increased by 100% with the addition of patients who received bup/nal after a referral to the Addiction Medicine Team. The intervention with the greatest impact was RN education, demonstrating that peer-coaching and teaching by an interprofessional team is key to changing practice. Unfortunately, overall prescribing remains low, and ED physicians may still be hesitant to prescribe bup/nal and defer to the specialists. It is unclear if this is due to a low number of patients presenting with AOW, patients with contraindications to bup/nal, or ED physician factors. The next step is an audit of all patients with AOW to see what percentage of those eligible are treated with bup/nal. A follow up survey to determine ongoing barriers will inform further PDSA cycles.