Abstract

Methyprylon is a new non-barbiturate sedative-hypnotic. Its effects have been compared with those of chiorpromazine, meprobamate and pentobarbital on a variety of tests:

1) all four compounds depressed the spontaneous locomotor activity of rats.

2) all four compounds eliminated the extensor component of the maximum electroshock seizure in mice.

3) meprobamate, methyprylon and pentobarbital protected mice against clonic seizures in the anti-Metrazol assay; chlorpromazine did not show this effect.

4) chlorpromazine protected dogs against apomorphine-induced emesis in doses which produced no side effects. Methyprylon and pentobarbital produced protection in doses which caused ataxia. No protection was observed with meprobamate.

5) all four drugs produced large, slow waves in the EEG of dogs prepared by the thiopentai-C10 technique; the greatest EEG changes were produced by pentobarbital, followed by methyprylon, meprobamate and chlorpromazine.

6) all four drugs depressed the alerting response and lowered body temperature in trained, unanesthetized dogs. Chlorpromazine produced sedation without hypnosis in these dogs, whereas the other drugs produced ataxia followed by hypnosis. On the basis of doses causing equivalent duration of sleep, methyprylon is ¼ and meprobamate ⅛ as active as pentobarbital in the dog.