Determination of psilocin and 4-hydroxyindole-3-acetic acid in plasma by HPLC-ECD and pharmacokinetic profiles of oral and intravenous psilocybin in man
Felix Hasler, Daniel Bourquin, Rudolf Brenneisen, T. Bär, F.x. Vollenweider
Pharmaceutica Acta Helvetiae June 1, 1997 DOI: 10.1016/s0031-6865(97)00014-9 via OpenAlex
Summary
AI-generated from the abstractAfter oral ingestion of psilocybin, the main psychoactive compound in Psilocybe mushrooms, peak plasma levels of its metabolite psilocin occur around 105 minutes, averaging 8.2 ng/ml. Another metabolite, 4HIAA, peaks at about 113 minutes at 150 ng/ml. Intravenous administration produces psilocin peaks within roughly 2 minutes at 12.9 ng/ml, indicating rapid dephosphorylation of psilocybin. 4HIAA was not detected after intravenous dosing. The absolute oral bioavailability of psilocin from psilocybin is estimated at about 53%.
Study at a glance
| Characteristics | Controlled clinical study Peer reviewed |
|---|---|
| Sample size | 6 |
| Population | Healthy volunteers |
| Intervention | Psilocybin |
| Dose | 0.224 +/- 0.02 mg/kg b.wt. (10-20 mg) oral; 1 mg intravenous |
| Topics | Psilocybin |
| Keywords | Pharmacokinetics Chemistry High-performance liquid chromatography Bioavailability Microdialysis |
| Citations | 231 |
| Key finding | Oral psilocybin yields peak psilocin plasma levels at about 105 minutes with 53% bioavailability; intravenous psilocybin produces psilocin peaks within 2 minutes. |
Abstract
In order to investigate the pharmacokinetic properties of psilocybin (PY), the main psychoactive compound of Psilocybe mushrooms, high performance liquid chromatographic procedures with column-switching coupled with electrochemical detection (HPLC-ECD) for reliable quantitative determination of the PY metabolites psilocin (PI) and 4-hydroxyindole-3-acetic acid (4HIAA) in human plasma were established. Sample work-up includes protection of the highly unstable phenolic analytes with ascorbic acid, freeze-drying and in-vitro microdialysis. The data of two controlled clinical studies with healthy volunteers are presented. The subjects (N = 6 for both studies) received single oral PY doses of 0.224 +/- 0.02 mg/kg b.wt. (10-20 mg) and intravenous doses of 1 mg PY, respectively. Peak plasma levels of PI after oral administration of PY were measured after 105 +/- 37 min showing an average concentration of 8.2 +/- 2.8 ng PI/ml plasma. 4HIAA peak concentrations of 150 +/- 61 ng/ml plasma were found 113 +/- 41 min after ingestion of PY. After intravenous administration, a mean PI maximum plasma concentration of 12.9 +/- 5.6 ng/ml plasma was found 1.9 +/- 1.0 min after injection. The maximum plasma levels appearing within a very short period indicate a rapid dephosphorylation of PY also when administered systemically. 4HIAA was not detected after 1 mg of intravenous PY. Estimates for the absolute bioavailability of PI after oral administration of PY were 52.7 +/- 20% (N = 3).