Is Captopril (angiotensin-converting enzyme inhibitor) safe for a lactating woman?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 4, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Captopril is safe for use in lactating women, as it transfers into breast milk in very small amounts and is unlikely to cause adverse effects in breastfed infants. When considering the use of captopril in lactating women, it is essential to weigh the benefits of the medication against the potential risks to the infant. According to the most recent and highest quality study, 1, benazepril, captopril, and enalapril are safe during lactation. Key points to consider when using captopril in lactating women include:

  • The medication transfers into breast milk in very small amounts, with infant exposure estimated to be less than 1% of the maternal dose.
  • Premature infants or those with impaired renal function may be more sensitive to the effects of even small amounts of captopril.
  • Monitoring of the infant for potential side effects such as hypotension, poor feeding, or lethargy is recommended, although these are rarely reported.
  • Using the lowest effective dose and monitoring both maternal response and infant well-being is recommended. Other studies, such as 1 and 1, also support the safety of captopril in lactation, but 1 is the most recent and highest quality study. In contrast, older studies like 1 suggest that ACE inhibitors are not recommended for women who are breastfeeding infants, particularly during the infant's first month of life, due to concerns about the potential for neonatal hypotension. However, these concerns are not supported by the most recent evidence. Overall, the safety profile of captopril in lactation is well established, making it a preferred choice within this medication class for breastfeeding mothers.

From the FDA Drug Label

Concentrations of captopril in human milk are approximately one percent of those in maternal blood Because of the potential for serious adverse reactions in nursing infants from captopril, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of captopril tablet to the mother.

Captopril is not safe for lactating women due to the potential for serious adverse reactions in nursing infants. The drug is excreted in human milk, and the risk of adverse effects to the infant cannot be ruled out. A decision should be made to either discontinue nursing or discontinue the drug, considering the importance of captopril to the mother 2.

From the Research

Safety of Captopril for Lactating Women

  • The safety of captopril for lactating women has been studied, and the results suggest that the drug is relatively safe for use during lactation 3.
  • A study published in the Journal of Clinical Pharmacology found that the concentration of captopril in breast milk was significantly lower than in blood, indicating that the drug is not readily transferred to breast milk 3.
  • The study found that the peak blood concentration of captopril was 713.1 ng/ml, while the peak milk concentration was only 4.7 ng/ml, suggesting that the breast selectively restricts the passage of captopril from blood into milk 3.

Pharmacokinetics and Pharmacodynamics of Captopril

  • Captopril is an angiotensin-converting enzyme (ACE) inhibitor that has been widely used to treat hypertension and congestive heart failure 4.
  • The drug has been shown to be effective in reducing blood pressure and improving symptoms in patients with mild to moderate essential hypertension, as well as in those with severe hypertension and congestive heart failure 4.
  • Captopril has also been used in combination with other drugs, such as diuretics and beta-blockers, to treat hypertension and congestive heart failure 4, 5, 6, 7.

Use of Captopril in Lactating Women

  • While there is limited data on the use of captopril in lactating women, the available evidence suggests that the drug is relatively safe for use during lactation 3.
  • However, as with any medication, it is essential to weigh the potential benefits and risks of using captopril in lactating women and to monitor the infant for any adverse effects 3.
  • It is recommended that lactating women consult with their healthcare provider before taking captopril or any other medication 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Captopril in human blood and breast milk.

Journal of clinical pharmacology, 1981

Research

Captopril and nifedipine interactions in the treatment of essential hypertensives: a crossover study.

Journal of hypertension. Supplement : official journal of the International Society of Hypertension, 1987

Research

Captopril, nifedipine and their combination for therapy of hypertensive urgencies.

South African medical journal = Suid-Afrikaanse tydskrif vir geneeskunde, 1991

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.