A 10-year retrospective review of exposures to volatile nitrites reported to the Victorian Poisons Information Centre.

Introduction: Volatile nitrites, such as amyl nitrite, are used recreationally to enhance sexual experience and provide a feeling of euphoria. They are associated with severe adverse reactions including methaemoglobinaemia and maculopathy. The aim of this study was to explore the epidemiology and clinical effects of volatile nitrite exposures reported to the Victorian Poisons Information Centre in Australia over a 10-year period.

Methods: This was a retrospective, observational study of poison centre call records. Data were extracted for all exposures to volatile nitrites reported from 2013 to 2022.

Results: There were 132 calls about volatile nitrites, representing 122 exposures, with a more than five-fold increase in the annual number of exposures (from five in 2013 to 26 in 2022). Ingestion (49.2%) and inhalation (27.9%) were the most common routes of exposure. Seventy-six (62.3%) patients reported one or more symptoms related to volatile nitrite exposure. The most common symptoms were light-headedness/dizziness (20.5%), oro-mucosal irritation (15.6%), ocular irritation (14.8%), nasal irritation (12.3%), and nausea/vomiting (9.8%). Less common, but potentially serious, adverse effects included methaemoglobinaemia (4.1%), hypoxia (1.6%) and hypotension (0.8%). Symptom severity was usually classified as minor (70/76, 92.1%) at the time of the poisons centre call. Fifty-four (44.3%) patients were either in the hospital when the poisons centre was contacted or were referred to the hospital by the poisons centre.

Discussion: The increase in reported volatile nitrite exposures observed in this study aligns with epidemiological data showing an increase in volatile nitrite usage in Australia. The findings about the nature of exposures and symptoms experienced can be used to inform harm reduction and education efforts for community members and health professionals.

Conclusions: Exposures to volatile nitrites reported to an Australian poisons centre increased between 2013 and 2022. More than 40% of exposures resulted in a hospital presentation. Methaemoglobinaemia was reported in 4.1% of cases.