Article Text
Abstract
Background Toxicity, such as hyperpyrexia, associated with the use of 3,4-methylenedioxymethamphetamine (MDMA; ‘ecstasy’) appears to be related to serum MDMA concentrations. However, there does not appear to be a similar association with the number of tablets ingested, suggesting variation in the tablet content of MDMA. Although work has shown this variation in other areas of the world, no studies have reported on the variation of MDMA content in UK ecstasy tablets.
Methods Ecstasy tablets seized from individuals attending nightclubs were analysed qualitatively to determine if they contained MDMA and quantitatively to determine the MDMA content per tablet.
Results The mean amount of MDMA hydrochloride in 101 seized ecstasy tablets was 58.7±22.9 mg per tablet, with a range of 20 mg to 131 mg per tablet. The majority (96.0%) of tablets contained less than 100 mg MDMA per tablet. There appeared to be a bimodal distribution of MDMA content at approximately 20–40 mg per tablet and 60–80 mg per tablet.
Conclusion There is variability in the MDMA content of ecstasy tablets in the UK. This variability could potentially put users at increased risk of acute harm due to inadvertent excess ingestion of MDMA, as they are unaware of the differences in the MDMA content. Repeat sampling and quantification of MDMA content of ecstasy tablets in the UK will allow better education of users about the potential harms associated with the variability in the MDMA content. In addition, it will provide information to allow the monitoring of changes in not only the MDMA content, but also other adulterants, in ecstasy tablets.
- acute toxicity
- drug abuse
- ecstasy
- MDMA
- mental health
- recreational drugs
- tablet analysis
- toxicology
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3,4-Methylenedioxymethamphetamine (MDMA; ‘ecstasy’) was first synthesised by Merck in 1912.1 Animal research on the behavioural effects of MDMA was first undertaken by the US army in 1953 and 1954, although this was not published in the public domain until 1973.2 Recreational use of MDMA as a ‘street drug’ appears to have first occurred in the early 1970s, following the control of 3,4-methylenedioxyamphetamine in the USA in 1970.
MDMA is associated with acute sympathomimetic toxicity characterised by hypertension, tachycardia, agitation/aggression and more significant, but less common, complications such as hyperpyrexia and hyponatraemia.3 It does appear that some of the acute toxicity related to MDMA is dose dependent as plasma MDMA concentrations correlate with complications such as hyperpyrexia.3 4 However, this correlation is not linked to the number of tablets that individuals report that they have used.3 This suggests that there is likely to be variation in MDMA tablet content.
Two previous studies have looked at the MDMA content of ecstasy tablets. The first of these was from Taiwan looking at drugs seized by law enforcement agencies; this showed that the mean±SD (range) MDMA content of 100 tablets analysed in 2004 was 100±30 mg (16–163 mg).5 A subsequent study in Ireland reported a mean±SD (range) MDMA content of 76.4±15.6 mg (41.5–117.5 mg) per tablet.6 Although the qualitative analysis of the contents of ‘amnesty bins’ has been described previously,7 there have been no published studies looking at the MDMA content of ecstasy tablets in the UK.
Methods
Tablet identification
Tablets in drugs seized from amnesty bins in nightclubs and late night venues in London and Swansea in 2006 were collected. Initial screening of the tablets was undertaken using the Marquis test, in which concentrated sulphuric acid and formaldehyde were added to a ground sample of each tablet. Those samples that turned a blue–black colour indicated the presence of MDMA,8 and were then subjected to further analysis by gas chromatography/mass spectrometry to confirm the presence of MDMA and high performance liquid chromatography (HPLC) to quantify the MDMA content of the tablet.
MDMA quantification
Quantification of the MDMA content of tablets was undertaken by HPLC with ultraviolet detection using metoclopramide as the internal standard. Tablet samples were ground using an agate pestle and mortar to homogenise them. From this homogenised sample, 25 mg was weighed out and dissolved in 5 ml of HPLC solvent, which also contained the internal standard. Following repeated inversion to facilitate dissolving of the homogenised sample, further dilutions with the HPLC solvent were undertaken to make a final 1 ml sample containing 250 μg/ml homogenised tablet sample and 35 μg/ml internal standard. A 200 μl sample of this final solution was used for the HPLC analysis.
MDMA standards were prepared from a standard stock solution containing 1 mg/ml MDMA in methanol, so that the final concentrations of MDMA for analysis when diluted with the internal standard (35 μg/ml) were 1 μg/ml, 5 μg/ml, 10 μg/ml, 25 μg/ml, 50 μg/ml and 100 μg/ml. The quantification of MDMA from the homogenised samples was undertaken in batches of 20, and the standard calibration curve was run after every 10 test samples.
Validation of results
The analysis and measurement of the MDMA concentration in the tablets was undertaken by sending 11 randomly selected samples to the Forensic Science Service (FSS) for duplicate analysis. MDMA quantification by the FSS was undertaken by the measurement of MDMA freebase. For appropriate comparison with the MDMA hydrochloride measurements undertaken by our study group, these results were converted into the equivalent MDMA hydrochloride concentration using the appropriate molecular weights.
Results
Tablet identification
One hundred and one tablets were screened and demonstrated to contain MDMA by Marquis testing; all of these underwent quantification of the MDMA content.
MDMA quantification
The mean amount of MDMA hydrochloride in each tablet analysed was 58.7±22.9 mg, with a range of 20–131 mg per tablet (figure 1). This, when standardised for the weight of individual tablets, represented an MDMA content of between 9% and 46% by weight. The majority (96.0%) of tablets contained less than 100 mg MDMA per tablet. There appeared to be a bimodal distribution of MDMA content: at approximately 20–40 mg per tablet and 60–80 mg per tablet (figure 1).
Validation of results
The comparison of the amount of MDMA hydrochloride in the 11 randomly selected samples analysed by both the study group at St George's, University of London, and the FSS is shown in figure 2. This shows that there was excellent correlation between the measurements undertaken by both laboratories, with an r2 value of 0.9871, validating the analysis undertaken by the study group.
Discussion
This study has shown that the MDMA content of tablets collected through amnesty bins in the UK is very variable. There is as much as a 6.5-fold difference in the MDMA content between those with the lowest content per tablet and those with the highest. This variation can become even more significant as, typically, users ingest more than one tablet in a single session. The MDMA content per tablet appeared to fall into two groups (20–40 mg per tablet and 60–80 mg per tablet).
The differences in MDMA content per tablet could put users at increased risk of acute MDMA toxicity. For example, an individual may take their usual two to three tablets not realising that the MDMA content may vary widely, at the extreme it could be the equivalent of them taking 12–18 tablets of the ‘low strength’ MDMA. In addition, users not achieving the desired effects because of reduced MDMA content in the tablets being used may increase the number of tablets used. There is the potential that different batches of tablets may be present within a venue or from the same dealer and so subsequent tablets may be contain greater amounts of MDMA, therefore putting the user at risk of significant acute toxicity.
This study used tablets from ‘amnesty bin’ seizures in nightclubs and late night venues in London and Swansea. Individuals attending nightclubs/late night venues may be searched as a requirement of entry. During this search any presumed recreational drugs found by security staff will be removed from the individual. In some areas these drugs are placed in police evidence bags and placed into locked ‘amnesty bins’ within the venue. The majority of these drugs are disposed of and detailed analysis is not undertaken. However, previous studies from our group have shown that analysis of these ‘amnesty bin’ samples can provide useful qualitative information on the local patterns of recreational drugs being used.7 9 This study has shown that quantitative analysis of amnesty bin samples can also be undertaken and add to the information provided from qualitative studies. There is the possibility to undertake repeated sampling to look at trends in both the actual drugs and the strength of the active ingredient(s) in these tablets.
Footnotes
Competing interests DMW and PID have acted as scientific advisors to the UK Advisory Council on the Misuse of Drugs (ACMD) and the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA).
Provenance and peer review Not commissioned; externally peer reviewed.