Pharmacology of ayahuasca administered in two repeated doses

Rafael G. Dos Santos, Eva Grasa, Marta Valle, Maria Rosa Ballester, José Carlos Bouso, Josep F. Nomdedéu, Rosa Homs, Manel J. Barbanoj, Jordi Riba

    Research output: Contribution to journalArticleResearchpeer-review

    56 Citations (Scopus)

    Abstract

    Rationale: Ayahuasca is an Amazonian tea containing the natural psychedelic 5-HT 2A/2C/1A agonist N,N-dimethyltryptamine (DMT). It is used in ceremonial contexts for its visionary properties. The human pharmacology of ayahuasca has been well characterized following its administration in single doses. Objectives: To evaluate the human pharmacology of ayahuasca in repeated doses and assess the potential occurrence of acute tolerance or sensitization. Methods: In a double-blind, crossover, placebo-controlled clinical trial, nine experienced psychedelic drug users received PO the two following treatment combinations at least 1 week apart: (a) a lactose placebo and then, 4 h later, an ayahuasca dose; and (b) two ayahuasca doses 4 h apart. All ayahuasca doses were freeze-dried Amazonian-sourced tea encapsulated to a standardized 0.75 mg DMT/kg bodyweight. Subjective, neurophysiological, cardiovascular, autonomic, neuroendocrine, and cell immunity measures were obtained before and at regular time intervals until 12 h after first dose administration. Results: DMT plasma concentrations, scores in subjective and neurophysiological variables, and serum prolactin and cortisol were significantly higher after two consecutive doses. When effects were standardized by plasma DMT concentrations, no differences were observed for subjective, neurophysiological, autonomic, or immunological effects. However, we observed a trend to reduced systolic blood pressure and heart rate, and a significant decrease for growth hormone (GH) after the second ayahuasca dose. Conclusions: Whereas there was no clear-cut tolerance or sensitization in the psychological sphere or most physiological variables, a trend to lower cardiovascular activation was observed, together with significant tolerance to GH secretion. © 2011 Springer-Verlag.
    Original languageEnglish
    Pages (from-to)1039-1053
    JournalPsychopharmacology
    Volume219
    Issue number4
    DOIs
    Publication statusPublished - 1 Feb 2012

    Keywords

    • Ayahuasca
    • Psychedelics
    • Repeated dose administration
    • Tolerance

    Fingerprint Dive into the research topics of 'Pharmacology of ayahuasca administered in two repeated doses'. Together they form a unique fingerprint.

    Cite this