Is Imipenem and Cilastatin safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Imipenem and Cilastatin. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
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.
Levels in milk
Maternal Levels. Imipenem 500 mg and cilastatin 500 mg were infused intravenously over 30 minutes in 12 women. Imipenem appeared in the milk in concentrations of 0.21 to 0.52 mg/L between 1 and 5 hours after the dose in 10 of the women. The drug was usually detectable in only 1 to 3 of the samples taken hourly for 6 hours. In one woman, imipenem was undetectable ( 0.2 mg/L) at all times up to 6 hours after the dose. Another woman had a detectable milk imipenem level of 1.84 mg/L only at 4 hours after the dose. Cilastatin was undetectable ( 0.5 mg/L) in milk at all times in all women.[ 1 ] Imipenem 500 mg and cilastatin 500 mg were infused intravenously over 30 minutes in 11 women. Seventy-six milk samples were obtained over the 6 hours following a dose. Imipenem was detectable in milk primarily at 2 to 4 hours after the dose. On average, the highest milk levels occurred 3 hours after the dose. All milk concentrations were less than 1 mg/L at all times up to 6 hours after the dose. The drug was undetectable in the milk of some women. Cilastatin was not measured.[ 2 ] Infant Levels. Relevant published information was not found as of the revision date.
“No published information” means the studies do not exist yet — not that Imipenem and Cilastatin is known to be harmful, and not that it is known to be safe. Your prescriber or pharmacist can weigh your baby's age and whether a better-studied alternative would do the same job. Worth asking before stopping a medicine you need.
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.