Acquired and Crossed Tolerance to Mescaline, LSD-25, and BOL-148

Tolerance to LSD-25 develops rapidly in both humans and animals, while tolerance to mescaline develops more slowly, as observed in rats. Crossed tolerance between LSD-25 and mescaline was previously demonstrated in three human subjects. The present study aims to confirm these findings and investigate whether rapid tolerance to mescaline occurs in humans, whether such tolerance confers resistance to LSD-25, and whether prolonged administration of BOL-148 produces tolerance to itself and to LSD-25.

Study at a glance

Abstract

It has been demonstrated experimentally that tolerance to the effects of lysergic acid diethylamide (LSD-25) develops rapidly, both in man1,4,6and in animals.5Tolerance to mescaline, with a less rapid development, was observed in rats by Freedman et al.5We are not aware of studies on tolerance to 2-bromo-d-lysergic acid diethylamide (BOL-148). Tachyphylaxis to LSD-25, it seems, is another problem which has yet to be investigated. In a previous research3performed by our group crossed tolerance was demonstrated, in three human subjects, between LSD-25 and mescaline. The purpose of the present study was to confirm our experimental results and to investigate whether rapid tolerance to mescaline also develops in humans, whether subjects having acquired such tolernce are resistant to LSD-25, whether protracted administration of BOL-148 gives a tolerance to this drug and to the chemically related LSD-25, and whether