Cross tolerance between LSD and psilocybin

  title={Cross tolerance between LSD and psilocybin},
  author={Harris Isbell and Albert B. Wolbach and Abraham Wikler and Edward J. Miner},
Summary1.In two experiments, using a cross-over design, the development of “direct” tolerance to LSD and psilocybin was measured after 10 (Experiment I) or 9 (Experiment II) volunteers had taken LSD in doses increasing to 1.5 meg/kg over the course of 6–7 days (Experiment I) or 13 days (Experiment II). On another occasion, the same patients received psilocybin in doses increasing to 150 mcg/kg over the course of 6–7 days (Experiment I) or 210 mcg/kg over the course of 13 days (Experiment II).2… 

Observations on direct and cross tolerance with LSD and d-amphetamine in man

The spectrum of LSD effects is different from that of d-amphetamine in single doses to nontolerant subjects and it is inferred that LSD and d- methamphetamine probably exert their effects through dissimilar mechanisms.

Cross tolerance between mescaline and LSD-25 with a comparison of the mescaline and LSD reactions

It was inferred that LSD, psilocybin and mescaline probably share common mechanisms of action or some common final pathway and patients receiving LSD daily became tolerant to mescalin and cross tolerant to LSD.

Metabolism of psilocybin and psilocin: clinical and forensic toxicological relevance

This review aims to discuss metabolism of psilocybin and psilocin, by presenting all major and minor psychoactive metabolites, with clinical and forensic relevance in diagnosis.

On the interaction of drugs with the cholinergic nervous system

Cross-tolerance to various muscarinic agonists and cholinesterase inhibitors was found in the physostigmine-tolerant mice and the tolerance was found to be reversible, with different rates of recovery, for the different effects.

The effect of N,N-dimethyltryptamine in human subjects tolerant to lysergic acid diethylamide

The spectrum of effects produced with single doses of N,N-dimethyltryptamine in 6 nontolerant human subjects resembled those produced with lysergic acid diethylamide (LSD), suggesting that the site or mechanism which is altered during LSD tolerance is not one which is primarily concerned with the action of DMT.

Tolerance and cross-tolerance to mescaline and amphetamine as a function of central and peripheral administration

There is further evidence that drugs administered directly into the CNS may not be producing their behavioral effects in the same manner as they do via peripheral administration, as a function of intraventricular or intraperitoneal routes of administration.

A study of the role of noradrenaline in behavioural changes produced in the rat by psychotomimetic drugs

  • M. F. Sugrue
  • Biology, Psychology
    British journal of pharmacology
  • 1969
The excitation induced by JB‐329 was abolished by reserpine pretreatment and was markedly reduced both in intensity and duration by the prior injection of α‐MT, and the peak behavioural effect was detected earlier.

On the interaction of drugs with the cholinergic nervous system

It was established that cyclohexamine is a better tolerance-inducer than phencylidine, although the nature of the tolerance developed for both drugs is qualitatively similar, and the significance of these results with respect to putative biochemical tolerance mechanisms is presented and discussed.

Tolerance and cross-tolerance among psychotomimetic drugs

A decrease in the amount of disruption of bar-pressing occurs with repeated daily administration of appropriate doses of all of the “psychotomimetic” compounds, and cross-tolerance was also demonstrated.



Comparison of the reactions induced by psilocybin and LSD-25 in man

  • H. Isbell
  • Biology, Psychology
  • 2004
After both drugs, abnormal mental states characterized by feelings of strangeness, difficulty in thinking, anxiety, altered sensory perception (particularly visual), elementary and true visual hallucinations, and alterations of body image were reported by the subjects.

Studies on lysergic acid diethylamide (LSD-25). I. Effects in former morphine addicts and development of tolerance during chronic intoxication.

The striking mental changes induced by the diethylamide of lysergic acid (hereafter referred to as LSD) have been studied extensively in Europe, Great Britain and the United States and are apparently the most effective and safest agent for inducing an experimental, but reversible, psychosis in nonpsychotic subjects.

Studies on lysergic acid diethylamide (LSD-25). III. Attempts to attenuate the LSD-reaction in man by pretreatment with neurohumoral blocking agents.

A hypothesis which ascribes the LSD psychosis to competition between LSD and serotonin for receptor sites on or in neurons, which might be termed the serotonin-deficiency theory, is based in part on the following evidence: Serotonin is found in brain, 6.

Studies on heptazone (6-morpholino-4,4-diphenyl-3-heptanone hydrochloride) in comparison with other analgesic drugs.

  • C. WinterL. Flataker
  • Psychology, Biology
    The Journal of pharmacology and experimental therapeutics
  • 1950
Cross-tolerance studies showed that methadone was able to break through a tolerance to morphine or Heptazone, and dogs rendered only moderately tolerant to Methadone were more tolerant to the other drugs used than to methamphetamineadone itself.

Psilocybin, ein psychotroper Wirkstoff aus dem mexikanischen RauschpilzPsilocybe mexicana Heim

The active principle ofPsilocybe mexicana Heim, a mexican mushroom with hallucinogenic properties, has been isolated in crystalline form. The compound has been given the namePsilocybin; it possesses


The last twenty years have seen a great increase in the use of statistical methods in various branches of science and technology. One of the obstacles to the more widespread use of these methods is

[Elucidation of the structure and the synthesis of psilocybin].

The structure of Psilocybin, the psychotropic active principle of the Mexican mushroomPsilocybe mexicana Heim, has been elucidated and the structure was confirmed by total synthesis.