PLACENTAL-TRANSFER OF N-ACETYLCYSTEINE FOLLOWING HUMAN MATERNAL ACETAMINOPHEN TOXICITY

Objective: To determine whether the antidote for acetaminophen poisoni ng, N-acetylcysteine, administered to pregnant women with acetaminophe n toxicity, crosses the placenta and can be measured in the newborn ci rculation following delivery, Design: Over a 15-month period, four pre gnant women with acetaminophen toxicity, who delivered their infants w hile receiving the antidote N-acetylcysteine, were studied, Maternal a nd cord blood from three viable infants, and cardiac blood sampled dur ing an autopsy on the fourth, were analyzed for the presence of N-acet ylcysteine using high-performance liquid chromatography, Maternal and cord blood aminotransferase activities, and autopsy findings on the no nviable infant were used to assess hepatic injury, Results: N-Acetylcy steine was detected in the cord blood of three viable infants and in c ardiac blood of a fourth, sampled at the time of autopsy, The mean N-a cetylcysteine concentration in cord blood was 9.4 mu g/mL (+1.3), This is well within the range associated with therapeutic doses of N-acety lcysteine typically administered to adults with acetaminophen poisonin g, No adverse sequelae developed in the three viable infants. The four th infant, delivered at 22 weeks gestational age died 3 h after birth, All mothers recovered and none of the four infants had evidence of ac etaminophen-related toxicity. Conclusions: This is the first study doc umenting placental transfer of N-acetylcysteine in humans and provides impetus for research establishing a direct antidotal effect of N-acet ylcysteine in the fetus.