Last update May 1, 2016


Low Risk

Possibly safe. Probably compatible. Mild risk possible. Follow up recommended. Read the Comment.

A macrolide antibiotic that is approved for pediatric use. Frequently used in young infants

At latest update no published data on excretion into breast milk were found.

It has higher molecular weight and shorter half-life elimination span than other macrolide antibiotics like azithromycin and claritormycin that are excreted into breast milk in negligible amount.
Until more published information about this drug regarding breastfeeding appears, it may be preferable a known and safer alternative, especially during the neonatal period and in cases of prematurity.

Early exposure to macrolide antibiotics (especially erythromycin) has been linked to hypertrophic pyloric stenosis, even through breast milk, being it a reason to avoid them during the first month of breastfeeding.

Take into account the possible negative results of bacterial cultures among febrile infants when their mothers are on antibiotics, as well as the possibility of gastroenteritis by altering the intestinal flora.


  • Clarithromycin ( Safe. Compatible. Minimal risk for breastfeeding and infant.)
  • Erythromycin (Possibly safe. Probably compatible. Mild risk possible. Follow up recommended. Read the Comment.)

Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

C42H69NO15 is Josamycin in Molecular formula.

Is written in other languages:

C42H69NO15 is also known as


C42H69NO15 belongs to this group or family:


Main tradenames from several countries containing C42H69NO15 in its composition:


Variable Value Unit
Oral Bioavail. 35 %
Molecular weight 828 daltons
Protein Binding 15 %
Tmax 1 hours
1.5 hours


  1. Periti P, Mazzei T, Mini E, Novelli A. Clinical pharmacokinetic properties of the macrolide antibiotics. Effects of age and various pathophysiological states (Part I). Clin Pharmacokinet. 1989 Abstract
  2. Wildfeuer A, Lemme JD. [The pharmacokinetics of josamycin]. Arzneimittelforschung. 1985 Abstract

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