Trends and Outcomes of Naloxone Use for Iatrogenic Opioid Overdose in Patients on General Wards in a Swiss Hospital: A Ten-Year Retrospective Case Series Analysis.

Introduction: Opioids carry an inherent high risk of adverse drug events (ADEs), although these are generally predictable and avoidable through proper management and monitoring. Naloxone, an opioid antagonist, is used to counteract severe opioid overdoses. Aim: This study aimed to estimate the incidence of iatrogenic opioid overdoses and describe prescribing patterns before, during and after them. Methods: We conducted a ten-year retrospective case series analysis of naloxone use among inpatients at a large, multisite university hospital in Switzerland from January 2014 to December 2023. Cases were included if an adult patient had received naloxone after opioid administration and overdose. We excluded patients who received naloxone during surgery or in intensive care units. Results: Of the 671 uses of naloxone identified, 121 (18.0%) met our inclusion criteria. Yearly naloxone use incidence was 11.0 per 10,000 inpatients, increasing slightly from 2014 to 2023. The median daily opioid dose requiring naloxone was 73 morphine milligram equivalents (MME). According to the Schumock and Thornton scale criteria, we considered 82 (67.8%) of the 121 opioid overdoses to have been potentially preventable The median opioid doses received before hospital admission (29.4 MME) were higher than at discharge (15.0 MME). Nevertheless, 71 (68.3%) of 104 discharged patients were still prescribed at least one opioid. Conclusion: This study found that iatrogenic opioid overdoses were relatively uncommon. However, the considerable number of preventable opioid overdoses estimated leads us to conclude that opioid stewardship programmes should be recommended across Switzerland.