FOR COMMUNITY PHARMACIST, new data will raise concerns about macrolides in pregnancy. We generally consider azithromycin or erythromycin safe in pregnancy. But clarithromycin is often avoided due to animal data showing birth defects, such as cleft palate...
Patients are now hearing that use of any macrolide during pregnancy might be linked to a higher risk of birth defects, particularly CV malformations, compared to penicillin. That's because a big, new study suggests that for every 1,000 moms who get a macrolide during pregnancy instead of penicillin, about 4 more babies may be born with a heart defect. But explain that this association is "driven" by first-trimester exposure to erythromycin for 5 to 7 days. And emphasize that this study doesn't PROVE that macrolides cause birth defects. Plus other studies suggest there's NOT a link.
Continue to rely on antibiotics considered generally safe during pregnancy like penicillins, cephalosporins, and clindamycin. But still feel comfortable recommending azithromycin in pregnancy when needed such as a single azithromycin 1 g dose plus IM ceftriaxone 250 mg to treat gonorrhea and chlamydia.
Educate that not treating infections can lead to adverse events, such as preterm delivery or serious neonatal eye infections. Try to avoid erythromycin or clarithromycin during pregnancy especially in the first trimester. For further information, see topic on Antibiotics use in pregnancy.
REFERENCES
Fan, H., Gilbert, R., O’Callaghan, F. and Li, L. (2020). Associations between macrolide antibiotics prescribing during pregnancy and adverse child outcomes in the UK: population based cohort study. BMJ, [online] 368. Available at: https://www.bmj.com/content/368/bmj.m331
Damkier, P., Brønniche, L.M.S., Korch-Frandsen, J.F.B. and Broe, A. (2019). In utero exposure to antibiotics and risk of congenital malformations: a population-based study. American Journal of Obstetrics and Gynecology, 221(6), pp.648.e1-648.e15. Available at: https://www.ajog.org/article/S0002-9378(19)30883-X/abstract
Mallah, N., Tohidinik, H.R., Etminan, M., Figueiras, A. and Takkouche, B. (2019). Prenatal Exposure to Macrolides and Risk of Congenital Malformations: A Meta-Analysis. Drug Safety. Available at: https://pubmed.ncbi.nlm.nih.gov/31721138