Opioid‐related adverse drug reactions in patients visiting the emergency division of a tertiary hospital

Opioid use and associated morbidity and mortality have increased in several countries during the past 20 years. We performed a study whose objective was to assess the frequency and causes of opioid‐related emergency division (ED) visits in an adult tertiary Swiss University Hospital over 9 weeks in 2018. We primarily assessed opioid‐related adverse drug reactions (ADR), secondary overdose, misuse, abuse, and insufficient pain relief. Current opioid use was identified in 1037 (8.3%) of the 12 470 included ED visits. In 64 opioid users, an ADR was identified as a contributing cause of the ED visit, representing 6.2% of opioid users, and 0.5% of the total ED visits. Moreover, we identified an overdose in 16 opioid users, misuse or abuse in 19 opioid users, and compatible withdrawal symptoms in 7 opioid users. After pooling all these events, we conclude that the ED visits could be related to opioid use in 10.2% of opioid users. Finally, in 201 opioid users, insufficient pain relief (pain not responding to the current pharmacological treatment) was identified as a contributing cause of ED visits. In these cases, other factors than simply pharmacological nonresponse may have been involved. In the context of an ever‐increasing opioid use to better control chronic pain situations, these results should reinforce emergency network epidemiological surveillance studies at a national level.