special subjects
Hallucinogens
Pathophysiology of Hallucinogen Intoxication
LSD, psilocybin, and many designer hallucinogens are serotonin receptor agonists. For mescaline, a phenylethylamine similar to Amphetamines , the exact mechanism has not been determined. Mode of use and effects vary: LSD is commonly taken orally from drug-impregnated blotter paper or as tablets. Onset of action is usually 30 to 60 minutes after ingestion; duration of effects can be 12 to 24 hours. Psilocybin is taken orally; effects usually last about 4 to 6 hours. Mescaline is taken orally as peyote buttons. Onset of effects is usually 30 to 90 minutes after ingestion; duration of effects is about 12 hours. DMT, when smoked, has onset in 2 to 5 minutes; duration of effects is 20 to 60 minutes (accounting for one of its street names, “businessman’s lunch”). A high degree of tolerance to LSD develops and disappears rapidly. Users tolerant to any of these hallucinogenic drugs are cross-tolerant to the other drugs. Psychologic dependence varies greatly; there is no evidence of physical dependence or a withdrawal syndrome. 