[Behavioral effects of ethyl loflazepate and its metabolites]

The behavioral effects of ethyl loflazepate and its metabolites were investigated in mice and rats, and they were compared with those of diazepam, nitrazepam and lorazepam. Locomotor activity of rats in open-field situation was increased with a wide range of doses of ethyl loflazepate and with large doses of nitrazepam. The anticonflict effect of ethyl loflazepate was slightly more potent than that of diazepam and much more potent than that of lorazepam. In suppressing muricide of both olfactory bulbectomized and raphe lesioned rats, ethyl loflazepate was approximately as potent as diazepam and much less potent than nitrazepam and lorazepam. Ethyl loflazepate was more potent than diazepam, nitrazepam and lorazepam in preventing pentetrazol-induced convulsion. In potentiating thiopental anesthesia in mice and impairing rotarod performance in mice and rats, ethyl loflazepate was less potent than diazepam, nitrazepam and lorazepam. The pharmacological activities of CM6913 and CM7116, metabolites of ethyl loflazepate, were approximately as potent as that of ethyl loflazepate. The duration of action of ethyl loflazepate was longer than those of the metabolites. These results indicate that ethyl loflazepate possesses pharmacological properties characteristic to benzodiazepines, and it is approximately equal to diazepam in potency and has a longer duration of action than diazepam, nitrazepam and lorazepam.