Therapeutic Drug Monitoring
May 21, 2008
Erin A Kolbrich, Robert S. Goodwin, David A. Gorelick et al.
127 citations
After a low oral dose of MDMA (1.0 mg/kg), average maximum plasma concentrations were 162.9 ng/mL for MDMA and 171.9 ng/mL for its metabolite HMMA. After a high dose (1.6 mg/kg), MDMA's average maximum concentration rose significantly to 291.8 ng/mL, while HMMA's remained unchanged at 173.5 ng/mL, indicating nonlinear pharmacokinetics. The half-lives of MDMA, MDA, and HMMA ranged from roughly 7 to 13.5 hours. This study provides the first MDMA plasma pharmacokinetic data from Black participants and female participants, with more frequent and extended sampling than prior work.
Journal of Analytical Toxicology
October 1, 2009
T. T. Abraham, Allan J. Barnes, Richie H. Lowe et al.
56 citations
After a single oral dose of MDMA (ecstasy), the drug and its metabolites are excreted in urine over an extended period, with the metabolite HMMA detectable longer than MDMA itself. In a double-blind study, healthy adult MDMA users received placebo, 1.0 mg/kg, or 1.6 mg/kg doses. From 916 urine specimens provided by 16 participants, median peak concentrations after the higher dose were 21,470 ng/mL for MDMA and 20,793 ng/mL for HMMA, with HMMA's last detection exceeding MDMA's by over 33 hours. In the first 24 hours, 30.2-34.3% of total urinary excretion occurred. Including HMMA in urine testing improves detection of MDMA exposure but requires hydrolysis of the sample.
Clinical Chemistry
January 23, 2009
Allan J. Barnes, Bruno Spinosa de Martinis, David A. Gorelick et al.
38 citations
In a controlled study, 15 healthy volunteers with prior MDMA use received placebo, low (1.0 mg/kg), and high (1.6 mg/kg) oral doses of MDMA in random order while wearing sweat patches for up to 7 days. MDMA was the main substance found in 59.7% of patches, with concentrations up to 3007 ng/patch; its metabolite MDA appeared in 29.4% of patches at lower levels, while other metabolites were undetected. At the 25-ng/patch threshold, 35% of patches were positive for MDMA. Sweat testing reliably detects MDMA use, but high variability in excretion means results should be interpreted qualitatively, not quantitatively.
Clinical Chemistry
October 7, 2011
Andrea E. Schwaninger, Markus R. Meyer, Allan J. Barnes et al.
33 citations
After oral MDMA (ecstasy) intake, human urine contains mostly sulfate and glucuronide conjugates of MDMA metabolites, with sulfates present at higher concentrations than glucuronides. More than 90% of the metabolites DHMA and HMMA were excreted as conjugates. HMMA sulfate had the longest detection window in urine. The ratio of HMMA sulfate to glucuronide was 2.0, and the ratio of DHMA 3-sulfate to 4-sulfate was 5.3 during the first 24 hours, matching predictions from earlier lab experiments. These findings can improve direct urine analysis for MDMA and its metabolites in clinical and forensic toxicology.
Biochemical Pharmacology
September 29, 2011
Andrea E. Schwaninger, Markus R. Meyer, Allan J. Barnes et al.
23 citations
The R- and S-enantiomers of MDMA are eliminated differently in human urine. After controlled oral doses of 1.0 and 1.6 mg/kg, urine from ten participants was analyzed. Over five days, a median of 21% of the measured compounds were excreted as R-stereoisomers and 17% as S-stereoisomers. Significantly more R-enantiomers of MDMA, DHMA, and HMMA sulfate were excreted, while more S-stereoisomers of HMMA and HMMA glucuronide were excreted. No significant differences appeared for MDA and DHMA sulfate. The ratio of R- to S-stereoisomers changed steadily over the first 48 hours, suggesting it could help estimate time of MDMA ingestion in clinical and forensic toxicology.
Therapeutic Drug Monitoring
October 1, 2011
Allan J. Barnes, Karl B. Scheidweiler, Erin A. Kolbrich-Spargo et al.
22 citations
Oral fluid testing can detect a single recreational dose of MDMA (70-150 mg) for 1 to 2 days after use. These findings from controlled administration studies give a scientific foundation for interpreting MDMA oral fluid test results.