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Thomas Kræmer

14 papers in the library · 835 citations · publishing 2002-2023

Papers

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Overcoming the clinical challenges of traditional ayahuasca: a first-in-human trial exploring novel routes of administration of N,N-Dimethyltryptamine and harmine.

Frontiers in Pharmacology 2023 Dario Dornbierer, Laurenz Marten, Jovin Mueller et al. 32 citations

Recently, the Amazonian plant medicine "ayahuasca"-containing the psychedelic compound N,N-dimethyltryptamine (DMT) and numerous β-carboline alkaloids, such as harmine-has been suggested to exhibit beneficial effects in patients with affective and other mental health disorders. Although ayahuasca ingestion is considered safe, its pharmacokinetics/pharmacodynamics and tolerability profile pose...

DOI: 10.3389/fphar.2023.1246892 (opens in new tab) Full text (opens in new tab) Psychedelics/entheogens/hallucinogens Drug-delivery/formulations/administration Ayahuasca/DMT/Harmine Pharmaceutical-innovation/drug-development

Comparative Untargeted Metabolomics Analysis of the Psychostimulants 3,4-Methylenedioxy-Methamphetamine (MDMA), Amphetamine, and the Novel Psychoactive Substance Mephedrone after Controlled Drug Administration to Humans

Metabolites July 27, 2020 Andrea E. Steuer, Daria Kaelin, Martina I. Boxler et al. 32 citations

Psychoactive stimulants are a popular drug class which are used recreationally. Over the last decade, large numbers of new psychoactive substances (NPS) have entered the drug market and these pose a worldwide problem to human health. Metabolomics approaches are useful tools for simultaneous detection of endogenous metabolites affected by drug use. They allow identification of pathways or...

Human Metabolome Changes after a Single Dose of 3,4-Methylenedioxymethamphetamine (MDMA) with Special Focus on Steroid Metabolism and Inflammation Processes

Journal of Proteome Research June 27, 2018 Martina I. Boxler, Gabriel L. Streun, Matthias E. Liechti et al. 23 citations

The intake of 3,4-methylenedioxymethamphetamine (MDMA) is known to increase several endogenous substances involved in steroid and inflammation pathways. Untargeted metabolomics screening approaches can determine biochemical changes after drug exposure and can reveal new pathways, which might be involved in the pharmacology and toxicology of a drug of abuse. We analyzed plasma samples from a...

Social Cognition and Interaction in Chronic Users of 3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy").

The International Journal of Neuropsychopharmacology April 1, 2018 Michael D. Wunderli, Matthias Vonmoos, Lorena Treichler et al.

The empathogen 3,4-methylenedioxymethamphetamine (MDMA) is the prototypical prosocial club drug inducing emotional openness to others. It has recently been shown that acutely applied 3,4-MDMA in fact enhances emotional empathy and prosocial behavior, while it simultaneously decreases cognitive empathy. However, the long-term effects of 3,4-MDMA use on socio-cognitive functions and social...

Discrete memory impairments in largely pure chronic users of MDMA.

European Neuropsychopharmacology October 1, 2017 Michael D. Wunderli, Matthias Vonmoos, Marina Fürst et al. 37 citations

Chronic use of 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy") has repeatedly been associated with deficits in working memory, declarative memory, and executive functions. However, previous findings regarding working memory and executive function are inconclusive yet, as in most studies concomitant stimulant use, which is known to affect these functions, was not adequately controlled for....

First Time View on Human Metabolome Changes after a Single Intake of 3,4-Methylenedioxymethamphetamine in Healthy Placebo-Controlled Subjects

Journal of Proteome Research July 19, 2017 Martina I. Boxler, Matthias E. Liechti, Yasmin Schmid et al. 17 citations

3,4-Methylenedioxymethamphetamine (MDMA; "ecstasy") is widely consumed recreationally. Little is known about its effects on the human metabolome. Mapping biochemical changes after drug exposure can complement traditional approaches by revealing potential biomarkers of organ toxicity or discovering new metabolomic features in a time- and dose-dependent manner. We aimed to analyze for the first...

DOI: 10.1021/acs.jproteome.7b00294 (opens in new tab) Metabolome Placebo Pharmacology Metabolite +1

Pharmacokinetics and Pharmacodynamics of Lysergic Acid Diethylamide in Healthy Subjects

Clinical Pharmacokinetics February 14, 2017 Patrick C. Dolder, Yasmin Schmid, Andrea E. Steuer et al. 134 citations

BACKGROUND AND OBJECTIVE: Lysergic acid diethylamide (LSD) is used recreationally and in clinical research. The aim of the present study was to characterize the pharmacokinetics and exposure-response relationship of oral LSD. METHODS: We analyzed pharmacokinetic data from two published placebo-controlled, double-blind, cross-over studies using oral administration of LSD 100 and 200 µg in 24 and...

Impact of Cytochrome P450 2D6 Function on the Chiral Blood Plasma Pharmacokinetics of 3,4-Methylenedioxymethamphetamine (MDMA) and Its Phase I and II Metabolites in Humans.

PLoS One June 15, 2016 Andrea E. Steuer, Corina Schmidhauser, Eva H Tingelhoff et al. 18 citations

3,4-methylenedioxymethamphetamine (MDMA; ecstasy) metabolism is known to be stereoselective, with preference for S-stereoisomers. Its major metabolic step involves CYP2D6-catalyzed demethylenation to 3,4-dihydroxymethamphetamine (DHMA), followed by methylation and conjugation. Alterations in CYP2D6 genotype and/or phenotype have been associated with higher toxicity. Therefore, the impact of...

Inhibition potential of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolites on the in vitro monoamine oxidase (MAO)-catalyzed deamination of the neurotransmitters serotonin and dopamine.

Toxicology Letters January 22, 2016 Andrea E. Steuer, Martina I. Boxler, Lorena Stock et al.

Neurotoxicity of 3,4-methylenedioxymethamphetamine (MDMA) is still controversially discussed. Formation of reactive oxygen species e.g. based on elevated dopamine (DA) concentrations and DA quinone formation is discussed among others. Inhibition potential of MDMA metabolites regarding neurotransmitter degradation by catechol-O-methyltransferase and sulfotransferase was described previously....

Chiral Plasma Pharmacokinetics of 3,4-Methylenedioxymethamphetamine and its Phase I and II Metabolites following Controlled Administration to Humans.

Drug metabolism and disposition: the biological fate of chemicals December 2015 Andrea E. Steuer, Corina Schmidhauser, Yasmin Schmid et al.

Generally, pharmacokinetic studies on 3,4-methylenedioxymethamphetamine (MDMA) in blood have been performed after conjugate cleavage, without taking into account that phase II metabolites represent distinct chemical entities with their own effects and stereoselective pharmacokinetics. The aim of the present study was to stereoselectively investigate the pharmacokinetics of intact glucuronide...

Chemistry, Pharmacology, Toxicology, and Hepatic Metabolism of Designer Drugs of the Amphetamine (Ecstasy), Piperazine, and Pyrrolidinophenone Types

Therapeutic Drug Monitoring March 19, 2004 Hans H Maurer, Thomas Kræmer, Dietmar Springer et al. 147 citations

Designer drugs of the amphetamine type (eg, MDMA, MDEA, MDA), of the new benzyl or phenyl piperazine type (eg, BZP, MDBP, mCPP, TFMPP, MeOPP), or of the pyrrolidinophenone type (eg, PPP, MOPPP, MDPPP, MPPP, MPHP) have gained popularity and notoriety as rave drugs. These drugs produce feelings of euphoria and energy and a desire to socialize. Although in the corresponding drug scene designer...

Concentrations and Ratios of Amphetamine, Methamphetamine, MDA, MDMA, and MDEA Enantiomers Determined in Plasma Samples from Clinical Toxicology and Driving Under the Influence of Drugs Cases by GC-NICI-MS*

Journal of Analytical Toxicology November 1, 2003 Frank T. Peters, Nele Samyn, Martin Wahl et al. 65 citations

Enantiomers of amphetamine (AM), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethylamphetamine (MDEA) exhibit different pharmacological properties. This may be important for the interpretation of analytical results. Plasma samples were analyzed using validated negative ion chemical ionization gas chromatography-mass...

DOI: 10.1093/jat/27.8.552 (opens in new tab) Full text (opens in new tab) MDMA Methamphetamine Pharmacology Forensic toxicology +2

Toxicokinetics of Amphetamines: Metabolism and Toxicokinetic Data of Designer Drugs, Amphetamine, Methamphetamine, and Their N-Alkyl Derivatives

Therapeutic Drug Monitoring April 1, 2002 Thomas Kræmer, Hans H Maurer 232 citations

This paper reviews the toxicokinetics of amphetamines. The designer drugs MDA (methylenedioxy-amphetamine, R,S-1-(3;,4;-methylenedioxyphenyl)2-propanamine), MDMA (R,S-methylenedioxymethamphetamine), and MDE (R,S-methylenedioxyethylamphetamine), as well as BDB (benzodioxolylbutanamine; R,S-1-(1;,3;-benzodioxol-5;-yl)-2-butanamine or R,S-1-(3;,4;-methylenedioxyphenyl)-2-butanamine) and MBDB...

DOI: 10.1097/00007691-200204000-00009 (opens in new tab) MDMA Toxicokinetics Methamphetamine Designer drug +4

Drugs of Abuse Monitoring in Blood for Control of Driving Under the Influence of Drugs

Therapeutic Drug Monitoring April 1, 2002 Manfred R. Moeller, Thomas Kræmer 98 citations

Driving under the influence of drugs is an issue of growing concern in the industrialized countries as a risk and a cause for road accidents. In forensic toxicology, the increasing number of samples for determination of drugs in blood is mainly due to zero-tolerance laws in several countries and well-trained police officers who can better recognize drivers under the influence of drugs of abuse....