Fosfomycin

The Basics

What is Fosfomycin?

Primarily used to treat bladder infections.

Brand names for Fosfomycin

Monurol

How Fosfomycin is classified

Antibacterial Agents, Anti-Infective Agents – Urinary

Fosfomycin During Pregnancy

Fosfomycin pregnancy category

Category B

Note that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.

What we know about taking Fosfomycin while pregnant

When administered intramuscularly as the sodium salt at a dose of 1 gm to pregnant women, fosfomycin crosses the placental barrier. MONUROL crosses the placental barrier of rats; it does not produce teratogenic effects in pregnant rats at dosages as high as 1000 mg/kg/day (approximately 9 and 1.4 times the human dose based on body weight and mg/m2, respectively). When administered to pregnant female rabbits at dosages as high as 1000 mg/kg/day (approximately 9 and 2.7 times the human dose based on body weight and mg/m2, respectively), fetotoxicities were observed. However, these toxicities were seen at maternally toxic doses and were considered to be due to the sensitivity of the rabbit to changes in the intestinal microflora resulting from the antibiotic administration. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, this drug should be used during pregnancy only if clearly needed.

Taking Fosfomycin While Breastfeeding

What are recommendations for lactation if you're taking Fosfomycin?

Limited information indicates that fosfomycin produces low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months.

Maternal / infant drug levels

Limited information indicates that fosfomycin produces low levels in milk and would not be expected to cause any adverse effects in breastfed infants, especially if the infant is older than 2 months.

Possible effects of Fosfomycin on milk supply

Relevant published information was not found as of the revision date.

Possible alternatives to Fosfomycin

Ciprofloxacin, Levofloxacin, Nitrofurantoin, Trimethoprim.