The epidemiology of acute methamphetamine toxicity presenting to emergency departments in Hong Kong

Introduction: Recreational use of methamphetamine is increasing worldwide, but epidemiology studies from Asia are lacking. We aimed to characterise the trends, drug use pattern, clinical presentations and health services utilisation of acute methamphetamine toxicity presenting to emergency departments and the current practice of emergency department psychosocial interventions in Hong Kong. Methods: This was a secondary analysis of a retrospective study on emergency department patients reported to the Hong Kong Poison Information Centre between 2010 and 2019 for acute toxicity related to recreational methamphetamine use. We studied the trend using a negative binominal regression model. Results: During the study period, 1225 episodes (involved 979 patients; 68.9% men; with a median age of 33.0 years) were reported. Acute methamphetamine toxicity did not increase significantly (odds ratio = 1.10, 95% confidence interval = 0.86–1.40, p = 0.46). Polysubstance abuse predominated. Many patients developed hypokalaemia (24.0%), rhabdomyolysis (17.2%), acute kidney injury (9.4%) and myocardial injury (4.7%); psychotic symptoms including auditory hallucination (23.8%) and paranoid delusion (21.1%); various acute behavioural disturbances and injuries. Overall, 66 patients required intensive care and 14 patients died. Only a minority of the patients were referred to social workers and voluntary drug treatment and rehabilitation services. Conclusion: Methamphetamine has a significant impact on physical and mental health in Hong Kong. Our findings highlight the need for screening for hypokalaemia, rhabdomyolysis, acute kidney injury, myocardial injury and psychosis in methamphetamine users and support policies that address polysubstance abuse, prevent drug use through continued public education and strengthen the referral system by integrating substance abuse services at the emergency department.