Levalbuterol Tartrate Interactions

Pregnancy & Breastfeeding

8.1 Pregnancy Teratogenic Effects: Pregnancy Category C There are no adequate and well-controlled studies of Levalbuterol tartrate HFA inhalation aerosol in pregnant women. Because animal reproduction studies are not always predictive of human response, Levalbuterol tartrate HFA inhalation aerosol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Rare instances of congenital anomalies, including cleft palate and limb defects, were reported in newborns of women treated with racemic albuterol in which the levalbuterol isomer (active drug substance of Levalbuterol tartrate HFA inhalation aerosol) is present. However, since multiple medications were taken during their pregnancies and there was no consistent pattern of anomalies, it was not possible to establish a relationship between racemic albuterol use and the occurrence of these congenital anomalies. In animal studies, oral administration of levalbuterol HCl to pregnant New Zealand White rabbits found no evidence of teratogenicity at doses up to 25 mg/kg/day (approximately 750 times the maximum recommended daily inhalation dose of levalbuterol tartrate for adults on a mg/m 2 basis). However, other studies demonstrated that racemic albuterol sulfate was teratogenic in mice and rabbits at doses slightly higher than the human therapeutic range. Pregnant mice administered racemic albuterol sulfate subcutaneously resulted in a dose-related increased incidence of cleft palate in their fetuses (4.5% of fetuses at 0.25 mg/kg/day or greater, corresponding to approximately 2 times MRDI dose, 9.3% of fetuses at 2.5 mg/kg/day, approximately 20 times MRDI dose of levalbuterol tartrate for adults on a mg/m 2 basis). The drug did not induce cleft palate formation when administered subcutaneously at a dose of 0.025 mg/kg/day (approximately 0.2 times MRDI dose of levalbuterol tartrate for adults on a mg/m 2 basis). In addition, oral administration of racemic albuterol sulfate to