Effect of successive administration of zopiclone, a new class of minor tranquillizer, on mouse liver microsomal mono-oxygenase system.

Oral administration of zopiclone to mice (10 mg/kg daily) for 14 days had no significant effect on body weight, liver weight, hepatic microsomal protein or cytochrome P-450 contents but produced significant increases in the activities of NADPH-cytochrome c reductase, NADH-ferricyanide reductase, aniline hydroxylation and aminopyrine N-demethylation.