Possible impact of the COVID-19 pandemic on the recreational use of nitrous oxide in the Paris area, France

INTRODUCTION: Recreational use of nitrous oxide (N(2)O) is increasing in Western countries, including France. During the COVID-19 pandemic, some authors warned that recreational N(2)O use could increase further as the supply of illicit drugs was impacted by various containment measures. METHODS: We retrospectively analyzed N(2)O exposures reported to the Paris Poison Control Center (France) from 2010/01/01 to 2021/04/15. The Poison Severity Score was used to grade severity. RESULTS: During the study period, 93 cases of N(2)O recreational exposures were reported (male/female ratio: 1.1; median age: 20.9 years range: [14.8-49.0]). The first case was reported in 2012, 84/93 (90%) and 65/93 (70%) were reported since 2019 and March 17(th) 2020 (first lockdown in France) respectively. Most of the patients were symptomatic (88/93; 95%) and developed neurological symptoms (78/93; 84%). Among the fourteen patients who developed moderate to severe symptoms, eleven were reported after March 2020. CONCLUSION: Despite a marked increase in recreational N(2)O exposures during the COVID-19 pandemic, the exact impact of COVID-19 on this increase remains to be determined as it was observed from 2019.