Can you take penicillin v 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 penicillin V 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. Penicillin V is acceptable in nursing mothers.
Quoted from Penicillin V — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised February 15, 2021.
How much penicillin v gets into breastmilk
Maternal Levels. Milk penicillin V levels were measured in 16 women after an oral dose of 1320 mg. In 7 women with mastitis, peak milk levels averaged 0.72 mg/L in the breast with mastitis and 0.58 mg/L without mastitis. In 4 women without mastitis (control), peak milk levels averaged 0.3 mg/L. Differences in the levels in mastitic milk and control milk were statistically significantly from nonmastitic milk in the women with mastitis in the opposite breast. In the women with mastitis, the peak level occurred 2.6 to 2.7 hours after the dose; in the women without mastitis, the peak occurred 5.4 hours after the dose. The average milk concentration and areas under the curve were greater in the women with mastitis, but the differences were not statistically significant. The authors estimated that an exclusively breastfed infant would receive an average daily dosage of about 50 mcg/kg (range 20 to 90 mcg/kg).
Infant Levels. Nursing mothers were given a single oral dose of 1320 mg of penicillin V. In two of the infants who were breastfed, urine penicillin V was measured 2 hours after nursing. In one it was undetectable and in the other, the urine concentration was 520 mcg/L.
What has been seen in breastfed infants
In one study, 12 infants were breastfed during maternal penicillin V therapy. Seven appeared normal, 3 had looser stools than normal, and 1 had a rash on the buttocks on the last day of therapy. These effects were possibly related to penicillin V in milk, but no control group was present. One infant had stains of blood in the stool, but it had happened once prior to maternal penicillin V treatment.
Effects on milk supply
Relevant published information was not found as of the revision date.
Frequently asked questions
Can you take penicillin v while breastfeeding?
Limited information indicates that penicillin V 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.
Does penicillin v pass into breastmilk?
LactMed's measured drug levels for penicillin v are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking penicillin v?
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 penicillin v
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.