Renal excretion profiles of psilocin following oral administration of psilocybin: a controlled study in man.
In a clinical study eight volunteers received psilocybin (PY) in psychoactive oral doses of 212+/-25 microg/kg body weight. To investigate the elimination kinetics of psilocin (PI), the first metabolite of PY, urine was collected for 24 h and PI concentrations were determined by high-performance liquid chromatography with column switching and electrochemical detection (HPLC-ECD). Sample workup included protection of the unstable PI with ascorbic acid, freeze-drying, and extraction with methanol. Peak PI concentrations up to 870 microg/l were measured in urine samples from the 2-4 h collection interval. The PI excretion rate in this period was 55.5+/-33.8 microg/h. The limit of quantitation (10 microg/L) was usually reached 24 h after drug administration. Within 24 h, 3.4+/-0.9% of the applied dose of PY was excreted as free PI. Addition of beta-glucuronidase to urine samples and incubation for 5 h at 40 degrees C led to twofold higher PI concentrations, although 18+/-7% of the amount of unconjugated PI was decomposed during incubation. We conclude that in humans PI is partially excreted as PI-O-glucuronide and that enzymatic hydrolysis extends the time of detectability for PI in urine samples.
Hasler
Felix
F
Heffter Research Center, Psychiatric University Hospital Zürich, Lenggstrasse 31, CH-8029 Zürich, Switzerland. fehasler@bli.unizh.ch
Bourquin
Daniel
D
Brenneisen
Rudolf
R
Vollenweider
Franz X
FX
D000284:Administration, Oral; D000328:Adult; D000339:Affect / Q000187:drug effects / Q000502:physiology; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011562:Psilocybin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000737:chemistry / Q000652:urine*
D011562:Psilocybin; C009105:psilocin