Psychopharmacological Studies of Lysergic Acid Diethylamide (LSD-25) Intoxication

Recent interest in psychotomimetic drugs has prompted a search for agents that block drug-induced hallucinations and psychological disturbances. Reports conflict: azacyclonol (Frenquel) was said to prevent LSD-25 psychoses, but one author could not confirm this. Chlorpromazine, serotonin, and reserpine have been reported to both ameliorate and intensify LSD-25 effects. Amobarbital sodium and chlorpromazine did not prevent intoxication but had suppressive effects at peak intoxication. The confusion stems from failing to distinguish true pharmacological antagonism (blocking) from suppression.

Study at a glance

Abstract

One consequence of the recent interest in psychotomimetic drugs has been a search for pharmacological agents that will "block" drug-induced psychological disturbances and hallucinations. Fabing1reported that azacyclonol (Frenquel) in small doses prevented the occurrence of lysergic acid diethylamide (LSD-25) "psychoses" in man, although one of us (L. D. C.) was unable to verify this observation.2Other investigators have reported that LSD-25 intoxication is ameliorated by premedication with chlorpromazine,3,4serotonin,5and reserpine.4However, it has also been reported that serotonin6and reserpine3intensify LSD-25 effects. Hoch7found that premedication with amobarbital (Amytal) sodium and chlorpromazine did not prevent LSD-25 or mescaline intoxication but pointed out that such drugs produced suppressive effects when given at the height of the intoxication. Several reasons exist for this confusing state of affairs. There has been a failure to distinguish between true pharmacological antagonism (blocking) and suppression.