OPEN Foundation

K. Cooper

High dose psilocybin is associated with positive subjective effects in healthy volunteers

June 27, 2018 / Mushrooms / Psilocybin, Mystical experiences, Papers, Psychiatry, Psychology, Publications / By / , , , , , ,

Abstract

AIM:
The aim of the current study was to investigate the relationship between escalating higher doses of psilocybin and the potential psilocybin occasioned positive subjective effects.
METHODS:
Healthy participants ( n=12) were given three escalating doses of oral psilocybin (0.3 mg/kg; 0.45 mg/kg; 0.6 mg/kg) or (18.8-36.6 mg; 27.1-54.0 mg; 36.3-59.2 mg) a minimum of four weeks apart in a supervised setting. Blood and urine samples, vital signs, and electrocardiograms were obtained. Subjective effects were assessed using the Mystical Experience Questionnaire and Persisting Effects Questionnaire.
RESULTS:
There was a significant linear dose-related response in Mystical Experience Questionnaire total score and the transcendence of time and space subscale, but not in the rate of a complete mystical experience. There was also a significant difference between dose 3 compared to dose 1 on the transcendence of time and space subscale, while no dose-related differences were found for Mystical Experience Questionnaire total scores or rate of a mystical experience. Persisting Effects Questionnaire positive composite scores 30 days after completion of the last dose were significantly higher than negative composite scores. Persisting Effects Questionnaire results revealed a moderate increase in sense of well-being or life satisfaction on average that was associated with the maximum Mystical Experience Questionnaire total score. Pharmacokinetic measures were associated with dose but not with Mystical Experience Questionnaire total scores or rate of a mystical experience.
CONCLUSIONS:
High doses of psilocybin elicited subjective effects at least as strong as the lower doses and resulted in positive persisting subjective effects 30 days after, indicating that a complete mystical experience was not a prerequisite for positive outcomes.
Nicholas, C. R., Henriquez, K. M., Gassman, M. C., Cooper, K. M., Muller, D., Hetzel, S., … & Hutson, P. R. (2018). High dose psilocybin is associated with positive subjective effects in healthy volunteers. Journal of Psychopharmacology, 0269881118780713.
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Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults

March 28, 2017 / Mushrooms / Psilocybin, Papers, Psychology, Psychopharmacology, Publications, Safety, Toxicology / By / , , , , , ,

Abstract

INTRODUCTION: Psilocybin is a psychedelic tryptamine that has shown promise in recent clinical trials for the treatment of depression and substance use disorders. This open-label study of the pharmacokinetics of psilocybin was performed to describe the pharmacokinetics and safety profile of psilocybin in sequential, escalating oral doses of 0.3, 0.45, and 0.6 mg/kg in 12 healthy adults.

METHODS: Eligible healthy adults received 6-8 h of preparatory counseling in anticipation of the first dose of psilocybin. The escalating oral psilocybin doses were administered at approximately monthly intervals in a controlled setting and subjects were monitored for 24 h. Blood and urine samples were collected over 24 h and assayed by a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for psilocybin and psilocin, the active metabolite. The pharmacokinetics of psilocin were determined using both compartmental (NONMEM) and noncompartmental (WinNonlin) methods.

RESULTS: No psilocybin was found in plasma or urine, and renal clearance of intact psilocin accounted for less than 2% of the total clearance. The pharmacokinetics of psilocin were linear within the twofold range of doses, and the elimination half-life of psilocin was 3 h (standard deviation 1.1). An extended elimination phase in some subjects suggests hydrolysis of the psilocin glucuronide metabolite. Variation in psilocin clearance was not predicted by body weight, and no serious adverse events occurred in the subjects studied.

CONCLUSIONS: The small amount of psilocin renally excreted suggests that no dose reduction is needed for subjects with mild-moderate renal impairment. Simulation of fixed doses using the pharmacokinetic parameters suggest that an oral dose of 25 mg should approximate the drug exposure of a 0.3 mg/kg oral dose of psilocybin. Although doses of 0.6 mg/kg are in excess of likely therapeutic doses, no serious physical or psychological events occurred during or within 30 days of any dose.

Brown, R. T., Nicholas, C. R., Cozzi, N. V., Gassman, M. C., Cooper, K. M., Muller, D., … & Hutson, P. R. (2017). Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults. Clinical Pharmacokinetics, 1-12. 10.1007/s40262-017-0540-6
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A Double-Blind, Randomized, Placebo-Controlled, Dose-Frequency Study of Intravenous Ketamine in Patients With Treatment-Resistant Depression

January 11, 2016 / Depression, Ketamine, Papers, Psychiatry, Psychology, Publications / By / , , , , , ,

Abstract

Objective:
Ketamine, an N-methyl-d-aspartate glutamate receptor antagonist, has demonstrated a rapid-onset antidepressant effect in patients with treatment-resistant depression. This study evaluated the efficacy of twice- and thrice-weekly intravenous administration of ketamine in sustaining initial antidepressant effects in patients with treatment-resistant depression.

Method:
In a multicenter, double-blind study, adults (ages 18–64 years) with treatment-resistant depression were randomized to receive either intravenous ketamine (0.5 mg/kg of body weight) or intravenous placebo, administered over 40 minutes, either two or three times weekly, for up to 4 weeks. Patients who discontinued double-blind treatment after at least 2 weeks for lack of efficacy could enter an optional 2-week open-label phase to receive ketamine with the same frequency as in the double-blind phase. The primary outcome measure was change from baseline to day 15 in total score on the Montgomery-Åsberg Depression Rating Scale (MADRS).

Results:
In total, 67 (45 women) of 68 randomized patients received treatment. In the twice-weekly dosing groups, the mean change in MADRS score at day 15 was −18.4 (SD=12.0) for ketamine and −5.7 (SD=10.2) for placebo; in the thrice-weekly groups, it was −17.7 (SD=7.3) for ketamine and −3.1 (SD=5.7) for placebo. Similar observations were noted for ketamine during the open-label phase (twice-weekly, −12.2 [SD=12.8] on day 4; thrice-weekly, −14.0 [SD=12.5] on day 5). Both regimens were generally well tolerated. Headache, anxiety, dissociation, nausea, and dizziness were the most common (≥20%) treatment-emergent adverse events. Dissociative symptoms occurred transiently and attenuated with repeated dosing.

Conclusions:
Twice-weekly and thrice-weekly administration of ketamine at 0.5 mg/kg similarly maintained antidepressant efficacy over 15 days.

Singh, J. B., Fedgchin, M., Daly, E. J., De Boer, P., Cooper, K., Lim, P., … & Kurian, B. (2016). A Double-Blind, Randomized, Placebo-Controlled, Dose-Frequency Study of Intravenous Ketamine in Patients With Treatment-Resistant Depression. American Journal of Psychiatry. http://dx.doi.org/10.1176/appi.ajp.2016.16010037
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30 April - Q&A with Rick Strassman

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