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Jordi Segura

Pompeu Fabra University

10 papers in the library · 1,183 citations · publishing 2000-2007

Papers

Human Pharmacology of MDMA

Therapeutic Drug Monitoring March 19, 2004 Rafael de la Torre, Magı́ Farré, Pere N. Roset et al. 445 citations

MDMA (ecstasy) is a widely misused psychostimulant that increases energy, euphoria, and sociability while also producing distinctive 'entactogen' effects such as feeling close to others and increased empathy. It works by promoting the release and blocking the reuptake of serotonin, dopamine, and norepinephrine. Acute toxic effects include serotonin syndrome, characterized by muscle rigidity, hyperreflexia, and hyperthermia. MDMA metabolism involves two main pathways; one is partially regulated by the polymorphic enzyme CYP2D6, but mechanism-based inhibition after two consecutive doses limits the impact of CYP2D6 genetics on acute toxicity. Metabolism may also contribute to long-term neurotoxic effects through progressive degeneration of the serotonergic system.

Pharmacology of MDMA in Humans

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.

Usefulness of Saliva for Measurement of 3,4-Methylenedioxymethamphetamine and Its Metabolites: Correlation with Plasma Drug Concentrations and Effect of Salivary pH

Clinical Chemistry October 1, 2001 Mèonica Navarro, Simona Pichini, Magí Farré et al. 135 citations

After a single 100-mg dose of MDMA, concentrations in saliva ranged from 1728.9 to 6510.6 μg/L, peaking at 1.5 hours, then declining to a mean of 126.2 μg/L at 24 hours. The saliva-to-plasma ratio varied from 32.3 to 1.2, with a peak of 18.1 at 1.5 hours. Salivary pH decreased by 0.6 units after drug administration, from a predose mean of 7.4 to 6.9 at 1.5 hours and 6.8 at 4 hours. Measuring MDMA in saliva offers a noninvasive alternative to plasma testing for clinical and toxicologic studies.

Determination of MDMA and its Metabolites in Blood and Urine by Gas Chromatography-Mass Spectrometry and Analysis of Enantiomers by Capillary Electrophoresis

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.

3,4-Dihydroxymethamphetamine (HHMA). A Major in Vivo 3,4-methylenedioxymethamphetamine (MDMA) Metabolite in Humans

Chemical Research in Toxicology August 2, 2001 Mireia Segura, Jordi Ortuño, Magı́ Farré et al. 105 citations

A new method using strong cation-exchange solid-phase extraction and high-performance liquid chromatography with electrochemical detection was validated for measuring the metabolite 3,4-dihydroxymethamphetamine (HHMA) in plasma and urine. Applied to samples from healthy volunteers given MDMA (ecstasy), HHMA appeared as a major metabolite, with peak plasma concentrations (154.5 microg/L) and overall exposure (AUC 1990.9 microg/L h) similar to those of MDMA itself. Urinary recovery of HHMA over 24 hours accounted for 17.7% of the 100 mg MDMA dose, raising total recovery of MDMA and its metabolites to 58%. The method is accurate and precise for pharmacokinetic studies, and measuring HHMA may help clarify its role in MDMA metabolism and potential neurotoxicity.

Usefulness of Sweat Testing for the Detection of MDMA after a Single-Dose Administration*

Journal of Analytical Toxicology July 1, 2003 Simona Pichini, M.d. Sánchez Navarro, Roberta Pacifici et al. 66 citations

After a single 100-mg dose of MDMA, the drug appears in sweat within 1.5 hours and peaks at 24 hours, but the amount varies up to 30-fold between individuals, ranging from 3.2 to 1326.1 ng per patch. Only traces of the metabolite MDA are detected. An onsite sweat strip test is positive at 1.5 hours, though 18% false-negative results occur in the first 6 hours. Sweat patch and onsite strip testing offer noninvasive ways to monitor MDMA use.

Cell‐Mediated Immune Response in MDMA Users After Repeated Dose Administration

Annals of the New York Academy of Sciences June 1, 2002 Roberta Pacifici, P. Zuccaro, Magı́ Farré et al. 58 citations

Repeated use of MDMA ('ecstasy') causes time-dependent immune dysfunction similar to a single dose, but the second dose extends the period of impaired immunocompetence. The drug decreases CD4 T-helper cells, increases natural killer (NK) cells, and reduces lymphocyte responsiveness to stimulation. In poor metabolizers, MDMA accumulation produces greater immunomodulatory effects, including significant differences in NK cell function. Recreational MDMA users show long-term alterations: reduced lymphocytes, T cells, and CD4 cells (though within normal limits), and NK cells reduced to one-third of healthy levels. Over two years, a subgroup showed statistically significant decreases in immune parameters, potentially increasing susceptibility to infection and immune disorders.

Immunomodulating Activity of MDMA

Annals of the New York Academy of Sciences September 1, 2000 Roberta Pacifici, P. Zuccaro, Magı́ Farré et al. 44 citations

MDMA (ecstasy) use produces neurochemical, behavioral, and endocrine changes similar to acute stress, acting as a chemical stressor. In rats, MDMA rapidly suppressed lymphocyte proliferation, decreased circulating lymphocytes, and increased plasma corticosterone. In humans, acute MDMA caused time-dependent immune dysfunction: CD4+ T-cells and lymphocyte responsiveness to stimulation decreased, while natural killer cells increased; total leukocyte count remained unchanged. Cortisol rose similarly to the rat model, suggesting MDMA triggers corticotrophin-releasing factor release from the hypothalamus, activating the HPA axis and sympathetic nervous system. These findings indicate MDMA ingestion may increase risk for immune system-related diseases.

Combined immunomodulating properties of 3,4‐methylenedioxymethamphetamine (MDMA) and cannabis in humans

Addiction May 22, 2007 Roberta Pacifici, Piergiorgio Zuccaro, Magı́ Farré et al. 39 citations

People who use both MDMA (ecstasy) and cannabis show long-term changes in immune function, including lower levels of interleukin-2 and higher levels of anti-inflammatory transforming growth factor beta-1, along with fewer total lymphocytes, CD4 cells, and natural killer cells. These immune alterations persisted over one year. Regular users of both drugs had a higher rate of mild infections compared to occasional users and those who used only cannabis or neither drug. Cannabis-only users showed intermediate immune changes. The findings suggest that sustained disruption of immune balance may lead to poorer general health and greater susceptibility to infections.

Non‐linear pharmacokinetics of MDMA (‘ecstasy’) in humans

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.