Pharmacokinetics of escalating oral doses of psilocybin in normal adult volunteers
Twelve healthy adult volunteers with psychedelic drug experience received oral doses of psilocybin of 0.3, 0.45, and 0.6mg/kg at 4-week intervals. Blood samples were collected at 0, 0.25, 0.5, 0.75, 1, 2, 3, 4, 6, 8, 12, 18, and 24hrs post-dose. Urine was collected for 24 hours after the dose. Psilocybin and psilocin concentrations were determined by a validated HPLC-MS-MS assay. No psilocybin was detectable in plasma or urine. The Cmax and AUC of the active metabolite psilocin were linear with dose level, and all doses were well tolerated. Less than 5% of the administered dose was found in the urine as psilocin. There were no serious adverse events. Positive psychological effects of psilocybin were similar across all three doses on the Mystical Experience Questionnaire and Persisting Effects Questionnaire (PEQ), with the exception of a dose 1 to dose 3 increase in the MEQ subscale Transcedence of Time and Space.
Dr. Randall Brown is an Associate Professor at the University of Wisconsin (UW) School of Medicine and Public Health. He was Co-Investigator and Medical Director for the UW’s pharmacokinetic study of psilocybin. He is Board Certified in Family Medicine and Addiction Medicine, and holds a PhD in Population Health Sciences. He has worked clinically in the care of patients with substance use disorders in multiple settings including specialist treatment programs, primary care clinics, hospitals, and methadone treatment facilities. He is the Director of the Center for Addictive Disorders at UW Hospital, the Director of UW’s Addiction Medicine Fellowship Program, and a member of the Board of Directors of the American Board of Addiction Medicine. His research interests center on the provision of care to patients with substance use disorders in general medical settings and through innovative systems interventions (such as mobile technology).