Is Nicardipine safe while breastfeeding?
Here is what LactMed, the Drugs and Lactation Database published by the U.S. National Institute of Child Health and Human Development (NICHD), reports about Nicardipine. The text below is quoted from that source — it is not our own verdict.
Summary of use during breastfeeding
Because of the low levels of nicardipine in breastmilk, amounts ingested by the infant are small and would not be expected to cause any adverse effects in breastfed infants. No special precautions are required.
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. Ten women were treated with oral nicardipine 4 to 14 days postpartum. Four received an immediate-release product 40 to 80 mg daily, and 6 received a sustained-release product 100 to 150 mg daily. Another woman received intravenous nicardipine 120 mg daily. The authors calculated that the infants received an average of 0.073% of the maternal weight-adjusted dose with the oral dosage and 0.14% of the maternal weight-adjusted dose with the intravenous dosage. They estimated that the average dosage that an infant would receive is about 0.3% of the projected infant dosage.[1]
Seven women received intravenous infusions of nicardipine for an average of 1.9 days in the immediate postpartum period as therapy for pre-eclampsia. Thirty-four milk samples were obtained at unspecified times; nicardipine was undetectable (<5 mcg/L) in 82% of samples. Four women receiving 1 to 6.5 mg/hour of nicardipine had 6 milk samples with detectable nicardipine ranging from 5.1 to 18.5 mcg/L. The highest concentration of 18.5 mcg/L was found in a woman receiving 5.5 mg/hour of nicardipine. The authors estimated that the maximum dose that could be received by a breastfed infant was less than 0.3 mcg daily or between 0.015 to 0.004% of a therapeutic dose in a 1 kg infant.[2]
Eighteen women with severe preeclampsia were given continuous infusion of nicardipine to control their blood pressure during pregnancy and postpartum. Blood and breastmilk samples were taken between 2 and 7 days postpartum from 17 of the women. The median postpartum nicardipine dosage was 0.54 mg/kg daily (mean 0.26 0.54 mg/kg daily; range 0.43 to 1.63 mg/kg daily). The median breastmilk nicardipine concentration in milk was 4.7 mcg/L (mean 6.9 mcg/L; range 2.3 to 37.7 mcg/L). Milk nicardipine levels were proportional to maternal plasma levels. The median weight-adjusted percentage of the maternal dose was 0.045% (mean 0.08%; range 0.006 to 0.33%).[3]
Infant Levels. Relevant published information was not found as of the revision date.
Alternatives LactMed lists
“No published information” means the studies do not exist yet — not that Nicardipine 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: Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development (NICHD), via NCBI Bookshelf, record “Nicardipine” (LM408). LactMed on NCBI Bookshelf. LactMed is a registered trademark of the U.S. Department of Health and Human Services.
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.