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.
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
December 19, 2007
Erin A Kolbrich, Ross H. Lowe, Marilyn A. Huestis
36 citations
A two-dimensional gas chromatography–mass spectrometry method with cryofocusing simultaneously quantifies MDMA, its metabolites MDA, HMMA, and HMA, and MDEA in human plasma. Limits of quantification were 1.0 μg/L for MDA and 2.5 μg/L for the other four compounds. Calibration curves were linear up to 100 μg/L for MDA and HMA and up to 400 μg/L for MDEA, MDMA, and HMMA, with correlation coefficients above 0.997. Extraction efficiencies from plasma were at least 85%, recoveries ranged from 85.6% to 107.2% of target, and intra- and interassay imprecision was below 8.5% at three concentrations. None of 66 tested exogenous compounds interfered. The assay achieves low quantification limits suitable for pharmacokinetic studies and may apply to other analytes and complex matrices.