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Mitona Pujadas

7 papers in the library · 435 citations · publishing 2001-2018

Papers

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.

Acute Pharmacological Effects of 2C-B in Humans: An Observational Study

Frontiers in Pharmacology March 13, 2018 Esther Papaseit, Marta Torrens, Mireia Ventura et al. 61 citations

2C-B, a psychedelic similar to mescaline, acts on serotonin receptors and produces mild psychedelic and stimulant-like effects. In an observational study, 16 healthy experienced users took 10–20 mg orally. The drug increased blood pressure and heart rate, elevated scores on scales for euphoria, liking, and stimulation, and altered perceptions of distances, colors, shapes, and lights. Five participants reported mild hallucinations. Peak 2C-B levels in saliva occurred at 1 hour, and peak cortisol at 3 hours. The effects resemble those of other serotonin-acting drugs.

Liquid chromatography-atmospheric pressure ionization electrospray mass spectrometry determination of "hallucinogenic designer drugs" in urine of consumers.

Journal of pharmaceutical and biomedical analysis June 9, 2008 Simona Pichini, Mitona Pujadas, Emilia Marchei et al. 59 citations

A liquid chromatography-mass spectrometry (LC-MS) method was developed to measure ten designer drugs—including MDMA, several 2C-series phenethylamines, m-CPP, and tryptamines—in urine samples from 32 consumers. Solid-phase extraction at pH 6 was applied to both non-hydrolyzed and enzymatically hydrolyzed urine, with 3,4-methylendioxypropylamphetamine (MDPA) as an internal standard. Chromatographic separation used a C18 column with a gradient of ammonium bicarbonate and acetonitrile, and detection was performed in single ion monitoring mode with electrospray ionization. Limits of quantification ranged from 20 to 60 ng/mL, calibration curves were linear to 2000 ng/mL, and mean recoveries were 55.4–95.6%. Higher analyte concentrations in hydrolyzed samples indicated the presence of conjugated compounds.

GC–MS Quantification Method for Mephedrone in Plasma and Urine: Application to Human Pharmacokinetics

Journal of Analytical Toxicology October 3, 2016 Eulàlia Olesti, Mitona Pujadas, Esther Papaseit et al. 41 citations

Mephedrone, a synthetic cathinone increasingly used by young people and linked to acute intoxication and fatalities, was studied in a controlled clinical trial. A gas chromatography-mass spectrometry method was developed to measure mephedrone in human plasma and urine. Six healthy men received 150 mg of mephedrone orally. Peak plasma concentration averaged 122.6 ng/mL, reached within 0.5–2 hours, and the drug was eliminated rapidly with a half-life of 2.2 hours. Less than 15% of the dose appeared unchanged in urine, and concentrations varied widely among individuals.

MDMA-Induced Dissociative State not Mediated by the 5-HT2A Receptor

Frontiers in Pharmacology July 11, 2017 Drew J. Puxty, Johannes G. Ramaekers, Rafael de la Torre et al. 33 citations

A single 75 mg dose of MDMA produces a dissociative state, marked by feelings of depersonalization and derealization, in healthy recreational users. Blocking the 5-HT2 receptor with ketanserin did not prevent this effect, indicating that the 5-HT2 receptor does not mediate MDMA-induced dissociation. Heart rate correlated with the dissociative state after MDMA alone, but not when ketanserin was given, suggesting heart rate changes do not directly cause dissociation. Cortisol levels and MDMA blood concentrations showed no clear relationship with dissociation. The exact neurobiological mechanism remains unknown and may be relevant to MDMA's therapeutic use.

Inhibition ofMDMA‐induced increase in cortisol does not prevent acute impairment of verbal memory

British Journal of Pharmacology September 4, 2012 Kim P. C. Kuypers, Rafael de la Torre, Magı́ Farré et al. 23 citations

MDMA acutely impairs memory, but this effect is not caused by the rise in cortisol that MDMA also triggers. In a placebo-controlled, within-subject experiment with 17 polydrug MDMA users, blocking the cortisol increase with metyrapone (a cortisol synthesis inhibitor) did not prevent the memory deficit produced by a 75 mg dose of MDMA. Memory was tested at peak drug concentrations. The finding suggests that the neuropharmacological mechanism behind MDMA-induced memory impairment is independent of cortisol.