Behavioral and EEG effects of triazolam in comparison with those of diazepam

Abstract

Triazolam was 4 to 5 times as potent as diazepam in reducing hyperemotionality of either septal-lesioned or olfactory bulbectomized rats (O. B. rats), and in suppressing muricide in O. B. rats. This agent was equipotent with diazepam in inhibiting fighting behavior of long-term isolated mice, but was longer in duration of action. Triazolam was approximately 4 times more potent than diazepam in preventing pentetrazol convulsion, but was 10 times less potent in inhibiting maximal electroshock convulsion in mice. The muscle relaxant effect of triazolam as assessed by the inclined screen test was 34 times, and the effect on rotarod per formance was 17 times more potent than that of diazepam in mice. Triazolam (0.2~0.5 mg/kg i.v.) changed the EEG to a drowsy pattern in unanesthetized rabbits with a chronic electrode implant, and suppressed the EEG arousal response to auditory stimulation and electrical stimulation given to either the mesence phalic reticular formation or posterior hypothalamus. The limbic afterdischarges induced by either hippocampal or amygdaloid stimulation were also markedly inhibited by triazolam. These EEG effects of triazolam were qualitatively similar to, but were 4 to 5 times more potent than those of diazepam. These results indicate that triazolam is a potent tranquilizer with a longer duration of action, and the muscle relaxant effect is considerable as compared with diazepam. © 1978, The Japanese Pharmacological Society. All rights reserved.