Can you take cloxacillin while breastfeeding?
What LactMed says
The National Library of Medicine’s own summary, quoted in full. We do not write a verdict of our own on this question, and we do not compress theirs into a label.
Limited information indicates that cloxacillin produces low levels in milk that are not expected to cause adverse effects in breastfed infants. Occasionally disruption of the infant's gastrointestinal flora, resulting in diarrhea or thrush have been reported with penicillins, but these effects have not been adequately evaluated. Cloxacillin is acceptable in nursing mothers.
Quoted from Cloxacillin — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised November 15, 2024.
What LactMed would consider instead
LactMed ends this record by naming the drugs it would consider in place of cloxacillin. Whether any of them fits depends on what you are treating — this is the database’s list, not a recommendation from us.
- Cefazolin
- Cephalexin
- Dicloxacillin
- Floxacillin
- Oxacillin
- Methicillin
- Nafcillin
- Doxycycline
- Linezolid
- Minocycline
- Trimethoprim-Sulfamethoxazole
- Vancomycin
How much cloxacillin gets into breastmilk
Maternal Levels. No studies have reported milk levels after oral cloxacillin. After a single intramuscular dose of 500 mg of cloxacillin in 2 women, milk levels ranged from 0.1 to 0.3 mg/L between 1 and 6 hours after the dose.
Infant Levels. Relevant published information was not found as of the revision date.
What has been seen in breastfed infants
In a telephone follow-up study, 10 nursing mothers reported taking cloxacillin (dosage unspecified). Two mothers reported diarrhea in their infants. No rashes or candidiasis were reported among the exposed infants.
Effects on milk supply
Relevant published information was not found as of the revision date.
Frequently asked questions
Can you take cloxacillin while breastfeeding?
Limited information indicates that cloxacillin produces low levels in milk that are not expected to cause adverse effects in breastfed infants. The full record is quoted on this page, and the decision is one to make with the person who prescribed it — LactMed itself states it is not a substitute for professional judgement.
What can I take instead of cloxacillin while breastfeeding?
LactMed lists Cefazolin, Cephalexin, Dicloxacillin, Floxacillin, Oxacillin, Methicillin, Nafcillin, Doxycycline, Linezolid, Minocycline, Trimethoprim-Sulfamethoxazole, Vancomycin as alternate drugs to consider. That is the database's own list for this drug — whether any of them suits you depends on what you are treating.
Does cloxacillin pass into breastmilk?
LactMed's measured drug levels for cloxacillin are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking cloxacillin?
LactMed does not frame its records that way — it reports measured drug levels in milk and what has been observed in breastfed infants, which is what this page quotes. "Pump and dump" advice for a specific drug and dose should come from your clinician or a pharmacist, not from a general rule.
More on cloxacillin
LactMed states that the information it presents is not a substitute for professional judgement, and that you should consult your healthcare provider for breastfeeding advice related to your particular situation. Nothing on this page is medical advice.