Fosfomycin Disodium Interactions

Pregnancy & Breastfeeding

8.1 Pregnancy Risk Summary Available data from observational studies and pharmacovigilance reports with fosfomycin use in pregnant women are insufficient to identify a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Fosfomycin crosses the placental barrier. There are no animal data that meet current standards for nonclinical developmental toxicity studies. However, some reproductive toxicity data are available from published literature. Intravenous or intraperitoneal fosfomycin-sodium did not cause malformations in rabbits or rats, respectively, but showed evidence of fetotoxicity (see Data ). The clinical relevance of these animal data is uncertain. The 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 defect and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Data Animal Data Fosfomycin crosses the placenta in rats and rabbits. In rats administered intraperitoneal fosfomycin sodium on Days 7 to 17 of gestation (during organogenesis), there were increased numbers of dead or resorbed fetuses at 1500 mg/kg (approximately 0.8 times the recommended human dose of 18 g/day, based on body surface area comparisons), a dose associated with maternal toxicity . Rabbits were administered intravenous fosfomycin sodium on Days 6 to 18 of gestation (during organogenesis) at doses 800 mg/kg (approximately 0.9 times the recommended human dose). No malformations were observed in rabbits or rats after intravenous or intraperitoneal fosfomycin sodium, respectively. In a pre- and post-natal developmental study in rats (dosed intraperitoneally with fosfomycin tromethamine between gestational day 6 and postnatal Day 21), no effects were observed in first-generation offspring at doses up to