Can you take linezolid 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.
Linezolid is excreted into breastmilk in concentrations likely to be effective against staphylococcal strains found in mastitis. Limited data indicate that the maximum dose an infant would receive through breastmilk would be only 6 to 9% of the standard infant dose and that resulting infant serum levels are trivial. If the mother requires linezolid, it is not a reason to discontinue breastfeeding. Monitor the infant for possible effects on the gastrointestinal tract, such as diarrhea and vomiting.
Quoted from Linezolid — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised July 15, 2024.
What LactMed would consider instead
LactMed ends this record by naming the drugs it would consider in place of linezolid. Whether any of them fits depends on what you are treating — this is the database’s list, not a recommendation from us.
- Doxycycline
- Minocycline
- Trimethoprim-Sulfamethoxazole
- Vancomycin
How much linezolid gets into breastmilk
Maternal Levels. A 32-year-old lactating woman was given a single dose of 600 mg of linezolid orally. Milk samples were taken at 10 time points over the next 24 hours. The peak concentration of linezolid in breastmilk occurred 2 hours after the dose with a value of 12.4 mg/L. Milk concentrations fell with a half-life of 6.5 hours and were detectable up to 24 hours after the dose. Using the peak milk level data from this patient, an exclusively breastfed infant would receive an estimated maximum of about 2 mg/kg daily with the maximum recommended maternal dosage. The established maximum dosage of linezolid for infants is 30 mg/kg daily.
A woman was given oral linezolid 600 mg every 12 hours for methicillin-resistant Staph. aureus mastitis. She pumped milk from both breasts 8 times daily on days 1 and 14 of therapy. Peak breastmilk linezolid levels were 9.75 mg/L on day 1 and 18.73 mg/L on day 14. The authors calculated that a fully breastfed infant would receive 7.85% of the weight-adjusted maternal dosage on day 1 and 15.61% on day 14. Using the average milk level on day 14, a fully breastfed infant would receive a dosage of 1.84 mg/kg daily, which is less than the maximum dosage of linezolid for infants of 30 mg/kg daily.
A woman taking linezolid 600 mg orally every 12 hours donated breastmilk samples at various times over a 24 hour period after about 45 hours after the first dose. Breastmilk linezolid levels ranged from 3.5 to 12.2 mg/L, with the highest level shortly after a dose and the lowest shortly before the following dose.
Infant Levels. A random blood sample was taken from a breastfed (extent not stated) infant about 3 to 4 hours after a maternal dose and found to contain <0.2 mg/L of linezolid, although the time of the previous breastfeeding was not known. A breast milk sample obtained 1 hour after the infant's serum sample and 4 hours after linezolid administration was 8.9 mg/L.
What has been seen in breastfed infants
Relevant published information was not found as of the revision date.
Effects on milk supply
Relevant published information was not found as of the revision date.
Frequently asked questions
Can you take linezolid while breastfeeding?
Linezolid is excreted into breastmilk in concentrations likely to be effective against staphylococcal strains found in mastitis. 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 linezolid while breastfeeding?
LactMed lists Doxycycline, 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 linezolid pass into breastmilk?
LactMed's measured drug levels for linezolid are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking linezolid?
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 linezolid
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.