Peyote and mescaline exposures: a 12-year review of a statewide poison center database

Background. Peyote, a cactus containing the hallucinogen mescaline, has been used by Native Americans for thousands of years. Illicit use is also known to occur, but reports in the medical literature consist only of isolated case reports. Objectives. We sought to identify characteristics of patients with reported exposure to peyote or mescaline. Methods. We performed a retrospective review of the California Poison Control System database for the years 1997-2008 for all cases of single-substance human exposure using the search terms "peyote" and "mescaline." Results. There were a total of 31 single-substance exposures to peyote or mescaline. Thirty (97%) exposures were intentional; 30 (97%) exposures were through the oral route, whereas one patient (3%) insufflated mescaline powder. Five patients (16%) were managed at home, whereas the remainder patients were managed in a healthcare facility. Commonly reported effects included hallucinations, tachycardia, agitation, and mydriasis. Vomiting was reported in only one case. Conclusions. Although uncommonly encountered, use of peyote and mescaline was associated with clinically significant effects requiring treatment in a substantial number of patients. Clinical effects were usually mild or moderate, and life-threatening toxicity was not reported in this case series.