[Attempt at modification of the pharmacological and toxic effects of cocaine]

The increase in locomotor activity induced by cocaine (15 mg/kg, i.p.) in the mouse was antagonized by pretreatment with compounds which inhibited monoanimergic receptors such as phenoxybenzamine, chlorpromazine or methysergide. On the contrary, the lethal dose of cocaine in rats and mice was not reduced by these substances. These data suggest that monoamines are involved in mediating the motor activity of cocaine but not implicated in the toxic effect of the drug.