Disposition of MDMA and Metabolites in Human Sweat Following Controlled MDMA Administration

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.

Study at a glance

Abstract

Abstract Background: Understanding the excretion of 3,4-methylenedioxymethamphetamine (MDMA) and metabolites in sweat is vital for interpretation of sweat tests in drug treatment, criminal justice, and workplace programs. Methods: Placebo, low (1.0 mg/kg), and high (1.6 mg/kg) doses of oral MDMA were given double-blind in random order to healthy volunteers (n = 15) with histories of MDMA use. Participants resided on the closed clinical research unit for up to 7 days after each dose. Volunteers wore PharmChek® sweat patches (n = 640) before, during, and after controlled dosing. Patches were analyzed by solid phase extraction and GC-MS for MDMA, methylenedioxyamphetamine (MDA), 4-hydroxy-3-methoxyamphetamine (HMA), and 4-hydroxy-3-methoxymethamphetamine (HMMA). Limits of quantification (LOQ) were 2.5 ng/patch for MDMA and 5 ng/patch for HMA, HMMA, and MDA. Results: MDMA was the primary analyte detected in 382 patches (59.7%), with concentrations up to 3007 ng/patch. MDA was detected in 188 patches (29.4%) at <172 ng/patch, whereas no HMMA or HMA was detected; 224 patches (35.0%) and 60 patches (9.4%) were positive for MDMA and MDA, respectively, at the 25-ng/patch threshold proposed by the Substance Abuse and Mental Health Services Administration. Conclusions: Sweat testing was shown to be an effective and reliable method for monitoring MDMA use in this controlled MDMA administration study. However, variability in sweat excretion suggests that results should be interpreted qualitatively rather than quantitatively. These data provide a scientific database for interpretation of MDMA sweat test results.