Behavioral pharmacology of zopiclone.

The pharmacological properties of zopiclone, a cyclopyrrolone derivative, have been studied in comparison with diazepam, nitrazepam, and flurazepam, on behavioral tests in mice and rats, including open-field activity, Skinner box conflict test, hyperemotionality and muricidal behavior of olfactory bulbectomized or raphectomized rats, pentetrazol or electroshock convulsions, inclined screen, rotarod, and thiopental-, ether-, or ethanol-induced anesthesia. Zopiclone exhibited pharmacological properties qualitatively similar to those of benzodiazepines especially in conflict, aggressivity, and pentetrazol-induced convulsion tests. On the other hand, its myorelaxant activity was somewhat weaker than that of the reference drugs. The pharmacological effects of zopiclone were of short duration.