Formoterol Fumarate Interactions

Pregnancy & Breastfeeding

8.1 Pregnancy Risk Summary There are limited available data with formoterol fumarate inhalation solution use in pregnant women to inform a drug-associated risk of adverse developmental outcomes. Beta-agonists may interfere with uterine contractility (see Clinical Considerations). In animal reproduction studies, oral administration of formoterol fumarate to pregnant rats and rabbits caused increased fetal malformations (rats and rabbits), decreased fetal weight (rats), and increased neonatal mortality (rats) following administration of doses that produced exposures approximately 730 to 29,000 times the MRHD on a mg/m 2 or AUC basis. These adverse effects generally occurred at large multiples of the MRHD when formoterol fumarate was administered by the oral route to achieve high systemic exposures. No effects were observed in a study with rats that received formoterol fumarate by the inhalation route at an exposure approximately 300 times the MRHD (see Data). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Clinical Considerations Labor or delivery There are no adequate and well-controlled human studies that have studied the effects of formoterol fumarate inhalation solution during labor and delivery. Because of the potential for beta-agonists interference with uterine contractility, use of formoterol fumarate inhalation solution during labor should be restricted to those patients in whom the benefits clearly outweigh the risk. Data Animal Data In embryofetal development studies with pregnant rats and rabbits dosed throughout the period of organogenesis, formoterol fumarate did not cause malformations in either species. However, for pregnant rats dosed