Reproductive studies of NY-198 in rats. III. Perinatal and postnatal study.

ABSTRACT

Lomefloxacin (NY-198), a new antibacterial agent, was administered daily by gavage to groups of 22 pregnant female rats of the CD strain at dosages of 30, 100 or 300 mg/kg/day from Day 17 of gestation to Day 21 of lactation. Females were allowed to deliver their litters and the offspring were examined for growth and functional development. There was a slight maternal response at the highest dosage (300 mg/kg/day), including increased salivation after dosing, reduced food intake in the treated period of gestation and increased water intake during the lactation period. Gestation length was slightly increased, although remaining within the laboratory background control range; in consequence, body weight of F1 offspring at Day 1 post partum was slightly increased. At 100 mg/kg/day, a few females showed increased salivation after dosing and there was a slight increase in gestation length. Birth weight of F1 offspring was slightly increased at 30 and 100 mg/kg/day but all values were within laboratory background control ranges. The survival, functional responses and fertility of F1 offspring were essentially unaffected by NY-198. On the basis of the above results, 30 mg/kg/day was considered to be the no-effect level for the F0 females treated during late gestation and lactation whilst 300 mg/kg/day administered to the F0 females had no adverse effect upon their offspring.