Clinical investigations of the therapeutic potential of ayahuasca: rationale and regulatory challenges.
Ayahuasca is a hallucinogenic beverage that is prominent in the ethnomedicine and shamanism of indigenous Amazonian tribes. Its unique pharmacology depends on the oral activity of the hallucinogen, N,N-dimethyltryptamine (DMT), which results from inhibition of monoamine oxidase (MAO) by beta-carboline alkaloids. MAO is the enzyme that normally degrades DMT in the liver and gut. Ayahuasca has long been integrated into mestizo folk medicine in the northwest Amazon. In Brazil, it is used as a sacrament by several syncretic churches. Some of these organizations have incorporated in the United States. The recreational and religious use of ayahuasca in the United States, as well as "ayahuasca tourism" in the Amazon, is increasing. The current legal status of ayahuasca or its source plants in the United States is unclear, although DMT is a Schedule I controlled substance. One ayahuasca church has received favorable rulings in 2 federal courts in response to its petition to the Department of Justice for the right to use ayahuasca under the Religious Freedom Restoration Act. A biomedical study of one of the churches, the Uñiao do Vegetal (UDV), indicated that ayahuasca may have therapeutic applications for the treatment of alcoholism, substance abuse, and possibly other disorders. Clinical studies conducted in Spain have demonstrated that ayahuasca can be used safely in normal healthy adults, but have done little to clarify its potential therapeutic uses. Because of ayahuasca's ill-defined legal status and variable botanical and chemical composition, clinical investigations in the United States, ideally under an approved Investigational New Drug (IND) protocol, are complicated by both regulatory and methodological issues. This article provides an overview of ayahuasca and discusses some of the challenges that must be overcome before it can be clinically investigated in the United States.
McKenna
Dennis J
DJ
Center for Spirituality and Healing, Academic Health Center, University of Minnesota, C592 Mayo Memorial Building, Mayo Mail Code 505, 420 Delaware Street Southeast, Minneapolis, MN 55455, USA. mcken031@umn.edu
D031581:Banisteriopsis; D001938:Brazil; D002986:Clinical Trials as Topic / Q000331:legislation & jurisprudence* / Q000379:methods / Q000592:standards*; D006801:Humans; D007880:Legislation, Drug / Q000592:standards*; D015394:Molecular Structure; D004130:N,N-Dimethyltryptamine / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D011619:Psychotropic Drugs / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D014481:United States; D014486:United States Food and Drug Administration / Q000331:legislation & jurisprudence
D010936:Plant Extracts; D011619:Psychotropic Drugs; D004130:N,N-Dimethyltryptamine