MDMA (Ecstasy) tablets collected in the UK between 2001 and 2018 show increasing MDMA content over time, with median free-base content exceeding 100 mg for the first time in 2018. Analysis of 412 tablets revealed dramatic within-batch content variability, with differences up to 136 mg. Dissolution testing on 247 tablets showed that tablets can be categorized as fast-, intermediate-, or slow-releasing, but no tablet characteristics predicted dissolution classification, meaning users cannot know a tablet's release profile beforehand. Within-batch variation in dissolution rate was also observed. Rapid assessment of MDMA content alone does not account for variability in remaining tablets in a batch or dissolution profiles. High-content, slow-releasing tablets may cause delayed or prolonged toxicity, increasing risk of re-dosing if absorption is delayed.
Two deaths in the UK following DMT use occurred in the context of polydrug use, with both cases involving additional compounds that can increase serotonergic drive, potentially causing serotonin syndrome. DMT was detected in femoral blood at 0.23 mg/l and 0.24 mg/l. One case involved cocaine and amphetamine; the other involved venlafaxine and mirtazapine. A literature search found three previous fatalities after DMT use, all accidental, two during ayahuasca ceremonies. Polydrug use is increasingly common, and users of unregulated drugs should exercise caution when combining them with other unregulated drugs or prescribed medications.