Can you take kanamycin 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.
If kanamycin is required by the mother, it is not a reason to discontinue breastfeeding. Kanamycin is poorly excreted into breastmilk. Newborn infants apparently absorb small amounts of other aminoglycosides, but serum levels with typical three times daily dosages are far below those attained when treating newborn infections and systemic effects of kanamycin are unlikely. Older infants would be expected to absorb even less kanamycin. Because there is little variability in the milk kanamycin levels during multiple daily dose regimens, timing breastfeeding with respect to the dose is of little or no benefit in reducing infant exposure. Data are not available with single daily dose regimens. Monitor the infant for possible effects on the gastrointestinal flora, such as diarrhea, candidiasis (e.g., thrush, diaper rash) or rarely, blood in the stool indicating possible antibiotic-associated colitis.
Quoted from Kanamycin — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised July 15, 2024.
How much kanamycin gets into breastmilk
Maternal Levels. Among 4 women given a single 2 gram dose or kanamycin orally, milk levels were undetectable in two. In the other 2 women, kanamycin milk levels averaged 1.2 mg/L at 1 hour after the dose. At 3 hours after a dose, peak milk levels were 1.35 and 1.6 mcg/L. At 5 and 7 hours after a dose, kanamycin was undetectable in one mother and 1.16 and 1.11 mg/L, respectively, in the other. In the same study, 4 women were given a single 1 gram dose of kanamycin by intramuscular injection. Average milk levels were relatively constant from 0.5 to 8 hours after the injection at about 10 mg/L, except for a peak milk level of 18.4 mg/L at 1 hour after injection.
After administration of a single 1 gram dose of kanamycin intramuscularly to several women (exact number not stated), average kanamycin milk levels were as follows: undetectable at 1 hour; 0.1 mg/L at 2 hours; 0.3 mg/L at 4 hours; and 0.5 mg/L at 6 hours after the dose.
In 15 women given kanamycin 500 mg intramuscularly three times daily, average kanamycin milk levels were as follows: undetectable at 0.5 hour; 2.57 mg/L at 1 hour; 2.51 mg/L at 2 hours; 2.12 mg/L at 4 hours; 2.06 mg/L at 6 hours; and 1.6 mg/L at 8 hours after the dose.Using data from this study, an exclusively breastfed infant would receive an estimated maximum daily dosage of 386 mcg/kg with this maternal dosage regimen.
Infant Levels. Relevant published information was not found as of the revision date.
What has been seen in breastfed infants
Kanamycin was used as part of a six-drug regimen to treat a pregnant woman with multidrug-resistant tuberculosis during the first trimester of pregnancy and postpartum. The infant was breastfed (extent and duration not stated). At age 1.8 years, the child had failure to thrive, possibly due to tuberculosis contracted after birth, but was otherwise developing normally.
Effects on milk supply
Relevant published information was not found as of the revision date.
Frequently asked questions
Can you take kanamycin while breastfeeding?
If kanamycin is required by the mother, it is not a reason to discontinue breastfeeding. 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.
Does kanamycin pass into breastmilk?
LactMed's measured drug levels for kanamycin are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking kanamycin?
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 kanamycin
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.