The Basics
What is Azithromycin?
Used to treat respiratory, enteric and genitourinary infections and may be used for some sexually transmitted and enteric infections.
Brand names for Azithromycin
Zithromax
How Azithromycin is classified
Anti-Bacterial Agents
Azithromycin During Pregnancy
Azithromycin pregnancy category
Category BNote 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 Azithromycin while pregnant
Reproductive and development studies have not been conducted using IV administration of azithromycin to animals. Reproduction studies have been performed in rats and mice using oral administration at doses up to moderately maternally toxic dose concentrations (i.e., 200 mg/kg/day). These daily doses in rats and mice based on body surface area, are estimated to be 4 and 2 times, respectively, an adult daily dose of 500 mg. In the animal studies, no evidence of harm to the fetus due to azithromycin was found. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, azithromycin should be used during pregnancy only if clearly needed.
Taking Azithromycin While Breastfeeding
What are recommendations for lactation if you're taking Azithromycin?
Because of the low levels of azithromycin in breastmilk and use in infants in higher doses, it would not be expected to cause adverse effects in breastfed infants. Monitor the infant for possible effects on the gastrointestinal flora, such as vomiting, diarrhea, candidiasis (thrush, diaper rash). Unconfirmed epidemiologic evidence indicates that the risk of infantile hypertrophic pyloric stenosis might be increased by maternal use of macrolide antibiotics during the first two weeks of breastfeeding, but others have questioned this relationship. A single dose of azithromycin given during labor to women who were nasal carriers of pathogenic Staphylococcus and Streptococcus reduced the counts of these bacteria in breastmilk in one study.
Maternal / infant drug levels
Because of the low levels of azithromycin in breastmilk and use in infants in higher doses, it would not be expected to cause adverse effects in breastfed infants. Monitor the infant for possible effects on the gastrointestinal flora, such as vomiting, diarrhea, candidiasis (thrush, diaper rash). Unconfirmed epidemiologic evidence indicates that the risk of infantile hypertrophic pyloric stenosis might be increased by maternal use of macrolide antibiotics during the first two weeks of breastfeeding, but others have questioned this relationship. A single dose of azithromycin given during labor to women who were nasal carriers of pathogenic Staphylococcus and Streptococcus reduced the counts of these bacteria in breastmilk in one study.
Possible effects of Azithromycin on milk supply
In a double-blind, controlled study in Gambia, women who were nasopharyngeal carriers of Stapylococcus aureus, Streptococcus pneumoniae or group B streptococcus were given a single 2 gram dose of azithromycin during labor. Milk samples from women who received azithromycin had 9.6% prevalence of carriage of the organisms compared to 21.9% in women who received placebo. Nasopharyngeal carriage in mothers and infants was also reduced on day 6 postpartum.[9]
Possible alternatives to Azithromycin
Clarithromycin, Erythromycin.
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. Kelsey JJ, Moser LR, Jennings JC et al Presence of azithromycin breast milk concentrations: a case report. Am J Obstet Gynecol. 1994;170:1375-6. PMID: 8178871
2. Sutton AL, Acosta EP, Larson KB et al. Perinatal pharmacokinetics of azithromycin for cesarean prophylaxis. Am J Obstet Gynecol. 2015;212:812.e1-6. PMID: 25595580
3. Salman S, Davis TM, Page-Sharp M et al. Pharmacokinetics of transfer of azithromycin into the breast milk of African mothers. Antimicrob Agents Chemother. 2016;60:1592-9. PMID: 26711756
4. Sorensen HT, Skriver MV, Pedersen L et al. Risk of infantile hypertrophic pyloric stenosis after maternal postnatal use of macrolides. Scand J Infect Dis. 2003;35:104-6. PMID: 12693559
5. Lund M, Pasternak B, Davidsen RB et al. Use of macrolides in mother and child and risk of infantile hypertrophic pyloric stenosis: Nationwide cohort study. BMJ. 2014;348:g1908. PMID: 24618148
6. Goldstein LH, Berlin M, Tsur L et al. The safety of macrolides during lactation. Breastfeed Med. 2009;4:197-200. PMID: 19366316
7. Abdellatif M, Ghozy S, Kamel MG et al. Association between exposure to macrolides and the development of infantile hypertrophic pyloric stenosis: a systematic review and meta-analysis. Eur J Pediatr. 2019;178:301-14. PMID: 30470884
8. Almaramhy HH, Al-Zalabani AH. The association of prenatal and postnatal macrolide exposure with subsequent development of infantile hypertrophic pyloric stenosis: A systematic review and meta-analysis. Ital J Pediatr. 2019;45:20. PMID: 30717812
9. Roca A, Oluwalana C, Bojang A et al. Oral azithromycin given during labour decreases bacterial carriage in the mothers and their offspring: A double-blind randomized trial. Clin Microbiol Infect. 2016;22:565.e1-9. PMID: 27026482
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
