Accuracy of substance exposure history in patients attending emergency departments after substance misuse; a comparison with biological sample analysis.

CONTEXT: Acute toxicity caused by illicit substance use is a common reason for emergency department (ED) presentation. Knowledge of the substances involved is helpful for predicting and managing potential toxicity, but limited information is available about the accuracy of patient-reported substance exposure. This study assessed the accuracy of the history of exposure in those reporting use of a single substance by comparison with those identified by detailed toxicological analysis, focusing on synthetic cannabinoid receptor agonists (SCRA). METHODS: Adults (≥16 years) presenting between March 2015 and July 2021 to participating UK hospitals with toxicity after reporting use of a single illicit substance were included. Exposure details were documented from medical records and blood and/or urine samples analysed using high-resolution accurate mass liquid chromatography-mass spectrometry (HRAM LCMS). Sensitivity, specificity, and positive and negative predictive values of the exposure history were calculated by comparison with biological sample analysis ("gold standard"). RESULTS: Single substance exposure was reported for 474 (median age 33 years, IQR: 18 range 16-75, 80% males) patients. Analysis commonly identified multiple substances (Median 3, IQR 2-5). A history of exposure was documented for 121 of 151 patients where a SCRA or metabolite was detected on analysis (sensitivity 80.1%, 95% CI 72.9, 86.2%). Corresponding proportions were lower for 3,4-methylenedioxymethamphetamine (MDMA, 44/70, 62.9%., 95% CI 50.5%, 74.1%), heroin 41/108 (38.0% 95% CI 28.8-47.8%) and cocaine (22/56, 31.3%, 95% CI 20.9, 43.6%). CONCLUSIONS: Multiple undeclared substances were detected analytically in most patients reporting single substance use. Clinicians should be alert to the potential presence and toxicity of unreported substances when managing patients presenting after substance misuse.

Trends in hospital presentations following analytically confirmed synthetic cannabinoid receptor agonist exposure before and after implementation of the 2016 UK Psychoactive Substances Act.

BACKGROUND AND AIMS: The United Kingdom (UK) Psychoactive Substances Act (PSA), implemented on the 26th  May 2016, made the production, supply and sale of all non-exempted psychoactive substances illegal. The aim of this study was to measure trends in hospital presentations for severe toxicity following analytically confirmed synthetic cannabinoid receptor agonist (SCRA) exposure before and after implementation of the PSA. DESIGN: Observational study. SETTING: Thirty-four hospitals across the UK participating in the Identification of Novel Psychoactive Substances (IONA) study. PARTICIPANTS: A total of 627 (79.9% male) consenting individuals who presented to participating hospitals between July 2015 and December 2019 with severe acute toxicity and suspected novel psychoactive substances exposure. MEASUREMENTS: Toxicological analyses of patient samples were conducted using liquid-chromatography tandem mass-spectrometry. Time-series analysis was conducted on the monthly number of patients with and without analytically confirmed SCRA exposure using Poisson segmented regression. FINDINGS: SCRAs were detected in 35.7% (n = 224) of patients. After adjusting for seasonality and the number of active sites, models showed no clear evidence of an upward or downward trend in the number of SCRA exposure cases in the period before (incidence rate ratio [IRR], 1.12; 95% CI, 0.99-1.26; P = 0.068) or after (IRR, 0.97; 95% CI, 0.94-1.01; P = 0.202) the implementation of the PSA. There was also no clear evidence of an upward or downward trend in non-SCRA exposure cases before (IRR, 1.12; 95% CI, 0.98-1.27; P = 0.105) or after (IRR, 1.01; 95% CI, 0.98-1.04; P = 0.478) implementation of the PSA. CONCLUSIONS: There is no clear evidence of an upward or downward trend in the number of patients presenting to UK hospitals with severe acute toxicity following analytically confirmed synthetic cannabinoid receptor agonist exposure since the implementation of the Psychoactive Substances Act.

Measurement uncertainty in quantifying delta-9-tetrahydrocannabinol (THC) in blood using SPE and LC/MS/MS.

A method for the quantitative analysis of delta-9-tetrahydrocannabinol (THC, the main active ingredient of cannabis) in whole blood using solid phase extraction and LC/MS/MS has been developed. A bottom-up approach with method validation data was used to evaluate and estimate the measurement uncertainty (MU) of the analytical method. The sources of uncertainty were identified using a cause and effect diagram. The contribution of each uncertainty component was estimated and were combined to derive the overall uncertainty of the analytical method. The combined uncertainty was estimated to be 0.131 µg/L (<7%). At a 99.7% confidence level, the expanded uncertainty was 0.393 µg/L for a THC concentration of 2 µg/L in a whole blood sample. The calculations not only enable the laboratory to quantify the uncertainty associated with a quantitative result, but can also be used to identify the sources of uncertainty and determine if the analytical method can be improved. An open access Measurement Uncertainty Calculator (MUCalc) software has been developed using the method described in this paper.

Acute toxicity following analytically confirmed use of the novel psychoactive substance (NPS) methiopropamine. A report from the Identification of Novel psychoActive substances (IONA) study.

Objective: Use of the New Psychoactive Substance (NPS) methiopropamine was first reported in 2011, but there are limited data on its acute toxicity. We report 11 patients presenting with analytically confirmed methiopropamine use. Methods: Adults presenting to 26 hospitals in the UK with severe acute toxicity after suspected NPS use were recruited from March 2015 to April 2018. Clinical features were recorded and biological samples analysed using tandem mass spectrometry. Results: Methiopropamine was detected in 11 of 414 patients, with the last detection in August 2016. It was the only substance detected in one patient; other substances detected included other NPS in nine and conventional drugs of misuse in five. Common features included tachycardia (10/11), agitation (7/11), confusion (7/11), reduced level of consciousness (5/11), hallucinations (5/11) and a raised creatine kinase (7/11). The median length of hospital stay was 17 hours; ten were discharged without sequelae and one was transferred for in-patient psychiatric treatment. Conclusions: Methiopropamine was only detected during 2015 and 2016; most patients had other drugs detected, particularly other NPS. Raised CK was common but it is not possible to determine the degree to which this and other features could be contributed to by co-use of other substances.