Pregnancy & Breastfeeding
Pregnancy Teratogenic Effects: Pregnancy Category B In a teratology study of acetylcysteine in the rabbit, oral doses of 500 mg/kg/day (2.6 times the human mucolytic dose) were administered to pregnant does by intubation on days 6 through 16 of gestation. Acetylcysteine was found to be nonteratogenic under the conditions of the study. In the rabbit, two groups (one of 14 and one of 16 pregnant females) were exposed to an aerosol of 10% acetylcysteine and 0.05% isoproterenol hydrochloride for 30 and 35 minutes twice a day from the 6th through the 18th day of pregnancy. No teratogenic effects were observed among the offspring. Teratology and a perinatal or postnatal toxicity study in rats were performed with a combination of acetylcysteine and isoproterenol administered by the inhalation route. In the rat, two groups of 25 pregnant females each were exposed to the aerosol for 30 and 35 minutes, respectively, twice a day from the 6th through the 15th day of gestation. No teratogenic effects were observed among the offspring. In the pregnant rat (30 rats per group), twice-daily exposure to an aerosol of acetylcysteine and isoproterenol for 30 or 35 minutes from the 15th day of gestation through the 21st day postpartum was without adverse effect on dams or newborns. Reproduction studies of acetylcysteine with isoproterenol have been performed in rats and of acetylcysteine alone in rabbits at doses up to 2.6 times the human dose. These have revealed no evidence of impaired fertility or harm to the fetus due to acetylcysteine. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies may not always be predictive of human responses, this drug should be used during pregnancy only if clearly needed.