Aztreonam and Avibactam and Breastfeeding

Summary of use during lactation

Limited information indicates that aztreonam produces low levels in milk that are not expected to cause adverse effects in breastfed infants. Avibactam has not been studied in nursing mothers. Occasionally disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush, have been reported with beta-lactams, but these effects have not been adequately evaluated. Aztreonam-avibactam is acceptable in nursing mothers.

Drug levels in milk and infant serum

Maternal Levels. After a single intramuscular dose of aztreonam 1 gram in 6 women, peak milk levels averaging 0.3 mg/L occurred 6 hours after the dose. In 6 other women given a single 1 gram dose of aztreonam intravenously, peak milk levels averaged 0.2 mg/L at 2.4 hours after the dose. Aztreonam was detectable (detection limit 0.09 mg/L) in milk between 2 and 8 hours after the intramuscular dose and 1.5 and 8 hours after the intravenous dose.[1,2] After a single intravenous dose of aztreonam 1 gram, milk levels ranging from 0.4 to 1 mg/L occurred 1 to 5 hours after the dose in 10 women with little variation in milk levels during this time in each woman. On average, levels were slightly higher 2 hours after the dose, but in individuals the peak level occurred at various times between 1 and 4 hours.[3] Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

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

Effects on lactation and breastmilk

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

References

1. Fleiss PM, Devlin R, Richwald G, et al. Aztreonam excretion in human milk. Clin Pharmacol Ther 1984;35:240. doi:10.1038/clpt.1984.32
2. Fleiss PM, Richwald GA, Gordon J, et al. Aztreonam in human serum and breast milk. Br J Clin Pharmacol 1985;19:509-11.4039600 PubMed
3. Ito K, Hirose R, Tamaya T, et al. Pharmacokinetic and clinical studies of aztreonam in the perinatal period. Jpn J Antibiot 1990;43:719-26.2381040 PubMed