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. Fabing1 reported 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.2 Other investigators have reported that LSD-25 intoxication is ameliorated by premedication with chlorpromazine,3,4 serotonin,5 and reserpine.4 However, it has also been reported that serotonin6 and reserpine3 intensify LSD-25 effects. Hoch7 found 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.
CLARK LD, BLISS EL. Psychopharmacological Studies of Lysergic Acid Diethylamide (LSD-25) IntoxicationEffects of Premedication with BOL-128 (2-Bromo-d-Lysergic Acid Diethylamide), Mescaline, Atropine, Amobarbital, and Chlorpromazine. AMA Arch NeurPsych. 1957;78(6):653-655. doi:10.1001/archneurpsyc.1957.02330420113020