Experiments with animals on the combined action of procaine and barbiturates

Abstract

Procaine prolonged the sleep of guinea-pigs induced by pentobarbital. Procaine could re-induce sleep in guinea-pigs and rabbits after the apparent effects of pentobarbital or thiopental respectively had ceased. This is evidence of an hypnotic effect of procaine rather than of an influence on the elimination of the barbiturate. The hypnotic and the convulsive effects seem to represent two independent actions of procaine. The effect of procaine on the toxicity of pentobarbital was nearly additive. The effect of pentobarbital on the toxicity of prpcaine was antagonistic. The distribution of standard errors of the sleeping times allowed the conclusion that the duration of the sleep could be better predicted if induced by the combinatin of pentobarbital and procaine than by pentobarbital alone. However, we appeared to lose on the margin of safety with this combination of drugs.