Atropine, Scopolamine, and Ditran: Comparative Pharmacology and Antagonists in Man

Atropine, scopolamine, and Ditran, three centrally active anticholinergic compounds, were administered to 158 normal young men in a dose range broader than any previously reported in order for us to study serially their central and peripheral effects. The findings indicate that there are no qualitative differences in the actions of these compounds, but that there are differences in potency, in relative central affinity, and in time course of effects. The toxic effects of belladonna-related substances respond well to certain anticholinesterase substances, such as physostigmine, sarin, and tetrahydroaminoacridine (THA), but not to others (neostigmine and disopropyl phosphorofluoridate (DFP)), nor do they respond to the unrelated drug methylphenidate nor to the phenothiazines. The hallucinations, confusion, and incoherence produced by high doses of anticholinergic compounds seem best classified as simple delirium, rather than as 'psychotomimetic' or 'psychedelic' syndromes.