Annals of the New York Academy of Sciences
September 1, 2000
Rafael de la Torre, Magı́ Farré, P. N. Roset et al.
178 citations
Recreational doses of MDMA (50 to 150 mg) in healthy volunteers cause pupil dilation, increases in systolic and diastolic blood pressure, heart rate, and pupillary diameter. Oral temperature changes are biphasic: a slight decrease at 1 hour followed by increases at 2 and 4 hours. Psychomotor performance shows slight dose-dependent impairment. Plasma cortisol and prolactin concentrations rise markedly. The drug's elimination half-life is about 8-9 hours. Peak drug concentrations and physiological effects occur between 1 and 2 hours and return to baseline 4-6 hours after administration.
Journal of Analytical Toxicology
April 1, 2002
Nieves Pizarro, Jordi Ortuño, Mercè Farré et al.
113 citations
A gas chromatography-mass spectrometry method simultaneously measured MDMA and its metabolites MDA, HMMA, and HMA in plasma and urine from healthy volunteers given 100 mg of MDMA. Samples were hydrolyzed, extracted with solid-phase columns, and analyzed as trifluoroacyl derivatives. Linear calibration covered plasma and urine ranges of 25–400 ng/mL and 250–2000 ng/mL for MDMA and HMMA, and 2.5–40 ng/mL and 100–1000 ng/mL for MDA and HMA. A capillary electrophoresis method using (2-hydroxy)propyl-beta-cyclodextrin as chiral selector resolved enantiomers without derivatization, with linear ranges for each enantiomer of MDMA, MDA, and HMMA. Stereoselective disposition of MDMA and MDA was confirmed, while HMMA showed an enantiomer ratio near 1 and constant over time, contradicting MDMA findings.
British Journal of Clinical Pharmacology
February 1, 2000
Rafael de la Torre, Magı́ Farré, Jordi Ortuño et al.
MDMA (ecstasy) shows nonlinear pharmacokinetics in humans: as the dose increases, plasma concentrations rise disproportionately, meaning small dose increases lead to much higher drug levels. In a controlled trial with 14 healthy volunteers given 50–150 mg, urinary recovery of the metabolite HMMA stayed constant while MDMA recovery rose, suggesting saturation or inhibition of the demethylenation metabolic step. Nonrenal clearance was dose-dependent while urinary clearance remained constant. This nonlinearity occurs regardless of CYP2D6 genotype, implying that even moderate dose increases in recreational use can produce unexpectedly high plasma concentrations, raising the risk of acute toxicity for all users, not just the 10% genetically deficient in CYP2D6.