Mescaline is the principal hallucinogenic agent among several alkaloids present in peyote, a small bluish green spineless cactus that grows in dry and rocky areas of southwestern United States and northern Mexico. The scientific name of the cactus is Lophophora williamsii (Fig 20.3). The terms “peyote buttons”and “mescal buttons” refer to the round fleshy tops of the cactus which have been sliced off and dried. Some Native American churches use these buttons in their religious ceremonies. Each button contains the equivalent of 45 mg of mescaline. It is rapidly absorbed on ingestion.
Ingestion of 6 to 12 mescal buttons is required to induce a hallucinatory experience. Symptoms usually resolve in about 12 hours after ingestion.
· Phase of GI distress: (30 to 60 minutes)—Nausea, vomiting, diarrhoea (rare).
· Phase of sensory manifestations: (4 to 6 hours) —Vivid visual hallucinations, emotional lability, anxiety, panic reactions
Involves provision of a quiet dark environment, and calm reassurance. Diazepam may be given orally or intravenously.