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Marta Concheiro

Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, NY, USA.

2 papers in the library · 34 citations · publishing 2013-2025

Papers

Nonlinear Pharmacokinetics of (±)3,4-Methylenedioxymethamphetamine (MDMA) and Its Pharmacodynamic Consequences in the Rat

Drug Metabolism and Disposition October 19, 2013 Marta Concheiro, Michael H. Baumann, Karl B. Scheidweiler et al. 32 citations

MDMA, an illicit drug with potential clinical use for PTSD and anxiety, shows nonlinear accumulation in male rats due to metabolic autoinhibition. After doses of 2.5, 5, and 10 mg/kg, MDMA and its metabolite MDA increased more than proportionally with dose, while other metabolites remained constant. Serotonin syndrome severity correlated with MDMA concentrations, and core temperature correlated with MDA concentrations, suggesting distinct mechanisms for behavioral and hyperthermic effects. At 2.5 mg/kg, MDMA Cmax was 164 ± 47.1 ng/ml, with HHMA and HMMA as major metabolites and less than 20% converted to MDA. These findings, given similarities to human pharmacokinetics, support using rat data at clinically relevant doses.

Development and validation of an analytical method for the determination of select 4-position ring-substituted tryptamines in plasma by liquid chromatography–tandem mass spectrometry

Journal of Analytical Toxicology May 26, 2025 Malik Schoffner, Vamshikrishna Reddy Sammeta, Marilyn Naeem et al. 2 citations

A liquid chromatography–tandem mass spectrometry method was developed and validated to detect and quantify six 4-position ring-substituted tryptamines in plasma, including psilocybin, psilacetin, 4-Pro-DMT, and their metabolites psilocin and 4-HO-DPT. The method showed linearity from 0.5 to 100 ng/mL for most analytes (psilocybin from 5 to 100 ng/mL), with acceptable bias and imprecision. Matrix effects were minimal except for ion enhancement of psilocin and psilocybin. Extraction efficiency was about 50%. Applied to plasma from male rats given psilacetin, psilacetin was not detected, and psilocin concentrations ranged up to 32.7 ng/mL. The method provides a robust tool for future research and clinical applications.