Pharmacokinetics of Hoasca alkaloids in healthy humans
This open-label field study (n=15) investigated the pharmacokinetics, subjective, neuroendocrine, autonomic, and cardiovascular effects of ayahuasca (35.5 mg DMT, 158.5 mg THH, 29.7 mg Harmaline, 252.3 mg Harmine), providing a time-course of these parameters in a 24-hour period in the context of a religious ceremony.
Authors
- Charles Grob
- Deborah Mash
Published
Abstract
Introduction
N,N-Dimethyltryptamine (DMT), harmine, harmaline and tetrahydroharmine (THH) are the characteristic alkaloids found in Amazonian sacraments known as hoasca, ayahuasca, and yajè. Such beverages are characterized by the presence of these three harmala alkaloids, where harmine and harmaline reversibly inhibit monoamine oxidase A (MAO-A) while tetrahydroharmine weakly inhibits the uptake of serotonin. Together, both actions increase central and peripheral serotonergic activity while facilitating the psychoactivity of DMT. Though the use of such ‘teas’ has be known to western science for over 100 years, little is known of their pharmacokinetics.
Methods
In this study, hoasca was prepared and administered in a ceremonial context. All four alkaloids were measured in the tea and in the plasma of 15 volunteers, subsequent to the ingestion of 2 ml hoasca/kg body weight, using gas (GC) and high pressure liquid chromatographic (HPLC) methods.
Results
Pharmacokinetic parameters were calculated and peak times of psychoactivity coincided with high alkaloid concentrations, particularly DMT which had an average Tmax of 107.5±32.5 min.
Discussion
While DMT parameters correlated with those of harmine, THH showed a pharmacokinetic profile relatively independent of harmine’s.
Research Summary of 'Pharmacokinetics of Hoasca alkaloids in healthy humans'
Introduction
Hoasca (also called ayahuasca, yagé, daime and other names) is an Amazonian decoction prepared from Banisteriopsis caapi and Psychotria viridis that contains harmala alkaloids (harmine, harmaline, tetrahydroharmine, THH) together with N,N-dimethyltryptamine (DMT). Earlier pharmacology has identified harmine and harmaline as reversible inhibitors of monoamine oxidase A (MAO-A) and THH as a weak serotonin uptake inhibitor; these actions permit DMT to be orally active and increase serotonergic signalling. Despite a long history of ritual and medicinal use across the Amazon basin and an emerging research interest, the human pharmacokinetics of the tea’s characteristic alkaloids had been little described prior to this study. Callaway and colleagues set out to measure plasma concentrations and pharmacokinetic parameters of DMT, harmine, harmaline and THH following ingestion of hoasca in experienced ritual users, and to relate these concentrations to subjective, autonomic, cardiovascular and neuroendocrine responses. The study was conducted in a ceremonial context with volunteers from the União do Vegetal (UDV); analytical methods and psychometric evaluations were integrated into a prospective investigation of the tea’s acute pharmacology and pharmacokinetics.
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Study Details
- Study Typeindividual
- Journal
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- APA Citation
Callaway, J., McKenna, D., Grob, C., Brito, G., Raymon, L., Poland, R., Andrade, E., Andrade, E., & Mash, D. (1999). Pharmacokinetics of Hoasca alkaloids in healthy humans. Journal of Ethnopharmacology, 65(3), 243-256. https://doi.org/10.1016/S0378-8741(98)00168-8
References (1)
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