Hallucinogen
PREGNANCY RECOMMENDATION: Limited Human Data—Probably Compatible (Low Dose) Contraindicated (Recreational Use)
BREASTFEEDING RECOMMENDATION: No Human Data—Potential Toxicity (Low Dose) Contraindicated (Recreational Use)
PREGNANCY SUMMARY
Peyote is a hallucinogenic agent that is used legally in certain religious ceremonies. An active alkaloid in peyote is mescaline, an agent that causes developmental toxicity in animals. The use of peyote for religious rituals by certain Indian populations involves low doses and does not appear, based on limited data, to cause developmental toxicity. If true, this would be consistent with the principle that developmental toxicity is dose related. However, the apparent low risk of developmental toxicity in Native American populations using carefully monitored amounts of peyote probably is not transferable to the recreational use of peyote, and certainly not to the use of mescaline. Although the recreational use of peyote or mescaline in pregnancy has not been studied, the presumed higher doses might represent a risk to the embryo or fetus. In addition, the lifestyle of recreational users and the probable use of other hallucinogenic or abuse drugs might not be conducive to a healthy pregnancy. Therefore, such use should be discouraged in pregnancy and is classified as contraindicated.
FETAL RISK SUMMARY
The aboveground parts of peyote (Lophophora williamsii) are used primarily for their hallucinogenic properties. Other uses include orally for the treatment of fever, rheumatism, and paralysis, and topically for treating fractures, wounds, and snakebite (1). Scientific documentation of these uses has not been located. The active ingredient in peyote is mescaline, a chemical structurally related to amphetamines. It causes CNS and sympathetic stimulation. The effect on the CNS is similar to that of lysergic acid diethylamide (LSD) (1). (See also Lysergic Acid Diethylamide.)
A 1967 study used a single SC dose of mescaline (0.45, 1.33, or 3.25 mg/kg) in pregnant hamsters on day 8 (organogenesis) (2). Congenital malformations of the brain, spinal cord, liver, and other viscera were increased. The incidence of defects, however, was not dose-related as the lowest dose caused the greatest number of defects (28%), whereas the highest dose caused the fewest (9%). Resorptions (7%–25%), dead fetuses (5%–10%), and runts (5%–12%) were dose related (2).
A 1981 reproduction study with mescaline was conducted in hamsters (3). Oral doses of 16 and 32 mg/kg on the 7th through the 10th day of gestation resulted in dose-dependent increases in resorptions and corresponding decreases in litter size. The number of resorptions in controls and the two doses were 6.4%, 12.0%, and 48.8%, respectively. There also was a dose-related increased delay in the ossification of the skull, sternum, and metatarsals. No gross abnormalities were observed at necropsy (3).
Using an IV combination of carbon-14 labeled and unlabeled mescaline, investigators found that the drug crossed the placenta to the fetus in monkeys (4). Although the passage was limited by the high ionization at physiologic pH (99.3%) (pKa 9.56) and the low lipid solubility of nonionized mescaline, the drug crossed the placenta and concentrated, at various postinjection times, in the fetal organs. Low concentrations were found in fetal blood, brain, and cerebrospinal fluid (4). A similar study in mice, using only labeled mescaline given intraperitoneally, found that the drug crossed the placenta and concentrated in fetal organs with the lowest concentrations in fetal brain (5). Although one author stated that mescaline is known to cross the human placenta (6), such studies have not been located. The molecular weight (about 211) is low enough that exposure of the embryo and fetus should be expected. Passage across the human placenta should be limited by the ionization at physiologic pH and the low solubility of unionized mescaline found in the above monkey study.
A 1979 case report described a pregnancy in which the mother and father regularly used LSD, peyote, and marijuana during the first 4 months of gestation (7). The woman delivered a healthy 2951-g male infant without any abnormalities at about 38 weeks’ gestation. The infant was doing well at 8 months of age.
A brief 1970 review summarized the history, dosage, effects, and adverse effects of mescaline (8). Mescaline was only one of the then-known eight alkaloids present in peyote. Peyote has been used by some Mexican and American Indian tribes for hundreds of years and still is being used legally for religious rituals by the Native American Church. The author thought that mescaline, based on dosage, was the least potent of the commonly used hallucinogens (other hallucinogens not specified). The author also thought that mescaline might be teratogenic based on animal studies (8).
A 2001 review provided more information on the legal use of peyote and its pharmacology (6). Although L. williamsii is the cactus legally available and cultivated by the Native American Church, other members of the cactaceae family including Trichocercus pachanoi (San Pedro cactus) and Opuntia cylindrical also contain mescaline and other alkaloids. In addition to mescaline, about 50 alkaloids have been identified in these cacti. When peyote is used according to recommendations of the Native American Church, the risk for developmental toxicity was not thought to be increased. No increase in malformations was observed in Huichol Indians, a tribe that has used peyote as part of its religious rituals for centuries. However, based on the 1967 animal study cited above, the author concluded that risk of human developmental toxicity was associated with the recreational use of peyote and/or mescaline in which much higher doses than those in religious rituals are used. In addition, mescaline obtained on the street is often mislabeled and may not contain any mescaline at all. For example, phencyclidine (PCP), a much more potent and longer-lasting hallucinogen, is often labeled as mescaline (6). (See also Phencyclidine.)
BREASTFEEDING SUMMARY
No reports describing the use of peyote or its active alkaloid mescaline during human lactation have been located. The molecular weight of mescaline (about 211) is low enough that excretion into breast milk should be expected. The effect of this exposure on a nursing infant is unknown. However, the use of low doses of peyote by adults in religious rituals often is associated with adverse effects, such as nausea, vomiting, and sympathomimetic effects (mydriasis, mild tachycardia, mild hypertension, diaphoresis, ataxia, and hyperreflexia) (6). Higher maternal doses that may be associated with recreational use of peyote, and certainly with mescaline, could cause these effects in a nursing infant. Thus, the recreational use of peyote or mescaline should be considered contraindicated.
References
1.Peyote. Natural Medicines Comprehensive Database. 5th ed. Stockton, CA: Therapeutic Research Faculty, 2003:1034–5.
2.Geber WF. Congenital malformations induced by mescaline, lysergic acid diethylamide, and bromolysergic acid in the hamster. Science 1967;158:265–7.
3.Hirsch KS, Fritz HI. Teratogenic effects of mescaline, epinephrine, and norepinephrine in the hamster. Teratology 1961;23:287–91.
4.Taska RJ, Schoolar JC. Placental transfer and fetal distribution of mescaline-14C in monkeys. J Pharmacol Exp Ther 1972;183:427–32.
5.Shah NS, Neely AE, Shah KR, Lawrence RS. Placental transfer and tissue distribution of mescaline-14C in the mouse. J Pharmacol Exp Ther 1973;184:489–93.
6.Gilmore HT. Peyote use during pregnancy. S D J Med 2001;54:27–9.
7.Warren RJ, Rimoin DL, Sly WS. LSD exposure in utero. Pediatrics 1970;45:466–9.
8.Olney RK. Mescaline. Tex Med 1972;68:80–2.