Falling methamphetamine-related presentations to a clinical toxicology unit during the COVID-19 pandemic

The COVID-19 pandemic has affected patterns of recreational drug use in Australia. A brief audit in a Western Australian ED suggested a drop in illicit drug related presentations,¹ while positive drug tests in Victorian prisons have fallen from 5.25% in March to 1.74% in June, a decrease of 67%.^{2, 3}

To investigate the effect of the COVID-19 pandemic on presentations relating to recreational drug use to our hospital, we undertook a retrospective review of toxicological presentations for the 6-month period following the declaration of COVID-19 as a global pandemic (12 March 2020 to 12 September 2020). This was then compared to the respective 6-month period in 2019.

The Clinical Toxicology Unit manages all patients who present with drug intoxication to the Princess Alexandra Hospital in Brisbane, Australia. The Princess Alexandra Hospital is a tertiary adult hospital with approximately 64 000 ED presentations annually. Data from every presentation to the unit are prospectively entered into a purpose-built database. This was searched for all presentations within the above date ranges. Descriptive statistics were used, with differences between groups compared with the χ² test. The Clinical Toxicology Unit has ethical approval to use its database and corresponding patient records for observational research (HREC/14/QPAH/308).

There were 1152 toxicology presentations during the study period, which is a 7% decrease of total activity compared to 2019 that saw 1245 presentations. However, the proportion of recreational drug use was similar in both periods with 623 presentations (54%) in 2020 and 665 (53%) in 2019.

Methamphetamine-related presentations decreased by 15% during the COVID period compared to the same period in 2019, representing a smaller proportion of the overall recreational drug presentations (353/625 [57%] in 2020 compared to 415/665 [62%] in 2019 [P = 0.04]) (Fig. 1). This shortfall in methamphetamine-related presentations was largely accounted for by a rise in gamma-hydroxybutyrate (GHB) presentations, which doubled from 24/665 (4%) in 2019 to 58/623 (9%) (P < 0.01). A smaller increase in marijuana-related presentations was also seen, rising from 55/665 (8%) to 73/623 (12%) (P = 0.04).

Decreased methamphetamine supply, because of travel restrictions, and an escalation in border security are suspected to have affected the pattern of methamphetamine use during the pandemic.⁴ Our patients report a significant increase in the cost of methamphetamine coupled with a decrease in methamphetamine quality since COVID restrictions have been in place. The increased number of GHB-related presentations was unexpected and suggests supply has been unaffected by the COVID restrictions. This may reflect better access to the GHB precursor gamma butyrolactone, which has a legitimate use as an industrial solvent.⁵ While restrictions are being relaxed across Australia, it is likely that access to methamphetamines will continue to be impacted by ongoing international border restrictions, which remain in place for a currently undefined period.

Our study is limited by its single centre, retrospective design. However, it raises an interesting observation of changing recreational drug exposures during a pandemic response that possibly reflect unintended consequence of public health measures to stem the transmission of COVID-19.