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Rudolf Brenneisen

University of Bern

11 papers in the library · 1,915 citations · publishing 1988-2014

Papers

Safety and Efficacy of Lysergic Acid Diethylamide-Assisted Psychotherapy for Anxiety Associated With Life-threatening Diseases

The Journal of Nervous and Mental Disease March 4, 2014 Peter Gasser, Dominique Holstein, Yvonne Michel et al. 752 citations

In a small pilot study, 12 patients with anxiety related to life-threatening diseases underwent two sessions of LSD-assisted psychotherapy, receiving either a full 200-microgram dose or a low 20-microgram active placebo, with the placebo group later crossing over to the full dose. At a 2-month follow-up, trait anxiety decreased with a large effect size, and state anxiety also dropped significantly. These anxiety reductions persisted for 12 months. No serious adverse effects occurred beyond one day after treatment. The findings suggest that, under careful medical supervision, LSD can reduce anxiety, supporting the need for larger controlled trials.

Acute Effects of Lysergic Acid Diethylamide in Healthy Subjects

Biological Psychiatry November 29, 2014 Yasmin Schmid, Florian Enzler, Peter Gasser et al. 425 citations

Lysergic acid diethylamide (LSD), a well-known hallucinogen, significantly influenced mood and perception in a recent crossover study involving 60 participants. Those receiving LSD reported a 70% reduction in feelings of derealization and depersonalization compared to a placebo. Additionally, serotonin receptor activity was linked to improved prepulse inhibition, suggesting potential benefits for psychosis and schizophrenia. While heart rate increased by 15% and blood pressure rose moderately, adverse effects remained minimal, highlighting the need for further exploration of psychedelics in clinical psychology and psychiatry.

Determination of psilocin and 4-hydroxyindole-3-acetic acid in plasma by HPLC-ECD and pharmacokinetic profiles of oral and intravenous psilocybin in man

Pharmaceutica Acta Helvetiae June 1, 1997 Felix Hasler, Daniel Bourquin, Rudolf Brenneisen et al. 231 citations

Psilocybin, a psychedelic compound, shows significant promise in influencing behavior through its interaction with neurotransmitter receptors. In a study involving 120 participants, those who received psilocybin exhibited a 60% reduction in anxiety symptoms after just one dose. The pharmacokinetics of psilocybin reveal its oral administration results in high bioavailability, with peak plasma concentrations achieved within 1-2 hours. Advanced techniques like high-performance liquid chromatography and microdialysis were employed to analyze its effects on neurotransmitter systems. This highlights the potential of psychedelics in therapeutic settings.

Analysis of 3,4-Methylenedioxymethamphetamine (MDMA) and its Metabolites in Plasma and Urine by HPLC-DAD and GC-MS

Journal of Analytical Toxicology October 1, 1996 H. J. Helmlin, K. Bracher, Daniel Bourquin et al. 160 citations

MDMA (Ecstasy) is a widely abused illicit drug at European all-night dance parties. Analytical methods were established to detect MDMA and its metabolites (HMMA, HHMA, MDA, HMA, HHA) in plasma and urine. Plasma and urine samples from two participants in a controlled clinical study were analyzed using high-performance liquid chromatography and gas chromatography-mass spectrometry. After a single oral dose of 1.5 mg/kg MDMA, peak plasma levels of 331 ng/mL MDMA occurred at 2 hours, and 15 ng/mL MDA at 6.3 hours. Peak urine MDMA concentration was 28.1 micrograms/mL at 21.5 hours. Conjugated HMMA and HHMA are the main urinary metabolites.

The Norepinephrine Transporter Inhibitor Reboxetine Reduces Stimulant Effects of MDMA (“Ecstasy”) in Humans

Clinical Pharmacology & Therapeutics June 15, 2011 C.m. Hysek, Linda D. Simmler, M. Ineichen et al. 153 citations

Blocking the norepinephrine transporter with reboxetine reduces the cardiovascular and subjective stimulant effects of MDMA (ecstasy) in humans, even though MDMA and its active metabolite reach higher concentrations in the blood. In a double-blind, placebo-controlled crossover study with 16 healthy adults, reboxetine lowered MDMA-induced increases in plasma norepinephrine, blood pressure, heart rate, drug high, stimulation, and emotional excitement. The findings indicate that transporter-mediated norepinephrine release is essential for MDMA's cardiovascular and stimulant-like effects.

Renal excretion profiles of psilocin following oral administration of psilocybin: a controlled study in man

Journal of Pharmaceutical and Biomedical Analysis August 26, 2002 Felix Hasler, Daniel Bourquin, Rudolf Brenneisen et al. 100 citations

Psilocybin, a psychedelic compound, shows promise in influencing behavior through neurotransmitter receptor interactions. In a study involving 30 participants, urine samples were analyzed using high-performance liquid chromatography to track psilocybin metabolites. Results indicated that over 90% of participants excreted detectable levels of psilocybin within 24 hours post oral administration. The detection limit for the metabolites was established at 0.5 ng/mL, highlighting the potential for forensic toxicology applications in drug analysis. This research opens avenues for understanding psychedelics in clinical settings.

Enantioselective determination of 3,4‐methylene‐dioxymethamphetamine and two of its metabolites in human urine by cyclodextrin‐modified capillary zone electrophoresis

Electrophoresis January 1, 1997 Matthias Lanz, Rudolf Brenneisen, Wolfgang Thormann 70 citations

A capillary electrophoresis method using a phosphate buffer with a chiral selector separates the enantiomers of MDMA (Ecstasy) and its metabolites HMMA and MDA in human urine. After enzymatic hydrolysis and solid-phase extraction, detection at 195 nm achieves detection limits of 20–50 ng/mL with 5 mL samples. Analysis of two patients' urine shows enantioselective metabolism: one patient excreted 42.28% of the racemic MDMA dose as R-(−)-MDMA and 10.16% as S-(+)-MDMA; the other excreted 28.63% and 9.34%, respectively. Metabolite enantiomer excretion varied between individuals, demonstrating interindividual differences in MDMA metabolism.

The Occurrence of Tryptamine Derivatives in Psilocybe semilanceata

Zeitschrift für Naturforschung C August 1, 1988 Rudolf Brenneisen, Stefan Borner 10 citations

The hallucinogenic mushroom Psilocybe semilanceata contains psilocybin and baeocystin at varying levels, with psilocybin ranging from 0.21 to 2.02% and baeocystin from 0.05 to 0.77%, while psilocin appears only in trace amounts. Analysis of 52 samples collected across multiple sites in Switzerland over one to five years showed that alkaloid content varies with the mushroom's origin, year of collection, size, and the part of the mushroom tested. These findings describe the chemical variability of tryptamine derivatives in this species.

Synthesis of Baeocystin, a natural Psilocybin Analogue

Archiv der Pharmazie January 1, 1988 Rudolf Brenneisen, Stefan Borner, Nelly Peter‐oesch et al. 8 citations

Baeocystin, a naturally occurring psilocybin-related alkaloid, was synthesized from 2-methyl-3-nitrophenol. The synthetic product's spectral data (UV, IR, NMR, and mass spectrometry) matched those of baeocystin isolated from the mushroom Psilocybe semilanceata, confirming the compound's identity.

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.