REPRODUCTIVE AND DEVELOPMENTAL TOXICITY STUDIES OF LANDIOLOL HYDROCHLORIDE (ONO-1101) (3) TERATOGENICITY STUDY IN RABBITS

A teratogenicity study oflandiolol hydrochloride (ONO-1101), a novel ultra short acting β-blocker, was conducted in KAR:NZW rabbits. ONO-1101 was administered intravenously at a dose level of 0 (control), 25, 50 or 100 mg/kg/day to pregnant rabbit from day 6 to 18 of gestation to examine the effects on dams and fetuses. Death occurred on 3 animals in the 100mg/kg/day group and one animal in the 50 mg/kg/day group during the treatment period. Hypoactivity, bradypnea/apnea and clonic convulsion after administration was observed in animal dosed 100 mg/kg/day. No maternal effects were seen on body weight, food consumption, necropsy findings or organ weights. External, skeletal and visceral findings revealed no adverse effects of ONO-1101 on fetuses. From the above results, it is estimated that the no-toxic dose level of ONO-1101 under these experimental conditions is 25 mg/kg/day for dams and 100 mg/kg for fetuses.