Enalapril is the angiotensin converting enzyme (ACE) inhibitor of choice during breastfeeding. Recommendations apply to full term and healthy infants only.

General considerations

It is important to complete an individual risk assessment for your patient and to apply the principles of prescribing in breastfeeding when looking at the available information and making treatment decisions.


Enalapril is the preferred angiotensin converting enzyme (ACE) inhibitor during breastfeeding as published evidence is available about its excretion into breast milk, it has been used therapeutically in infants, and it has the most favourable pharmacokinetics.

However, most ACE inhibitors can be used during breastfeeding if clinically appropriate.


Limited evidence shows milk levels of ACE inhibitors are low. Most ACE inhibitors are also metabolised to their active metabolite which is poorly absorbed orally. Therefore, any active metabolite in breast milk is also unlikely to be absorbed significantly by the infant via breast milk.


Recommendations apply to any indication the medicine is being used for, such as hypertension, heart failure or post-myocardial infarction.

Choice of antihypertensive

Choice of anti-hypertensive in breastfeeding will be dependent on a number of factors, including patient-specific characteristics, clinical condition and patient preference.

Drugs from different pharmacological classes may need to be used in combination and therefore their additive suitability in breastfeeding will need to be considered.

Treatment choice should primarily be directed at controlling symptoms, with safety in breastfeeding a secondary consideration.

See also our advice on beta-blockerscalcium-channel blockers and angiotensin-II receptor antagonists.

Breastfeeding itself can also help to reduce the risk of cardiovascular disease, including a protective effect against hypertension.

Infants at most risk of side-effects

Neonates and infants less than 2 months are at the most risk from the side-effects of ACE inhibitors, particularly hypotension, because they have underdeveloped clearance capacities, which means they can’t metabolise the medicines as effectively.

In addition, there is theoretical concern that ACE inhibitors could affect kidney development. However, this has not been proven or reported in any infants exposed to ACE inhibitors via breast milk.

If an ACE inhibitor is the best therapeutic option to treat the maternal condition, extra caution should be taken when breastfeeding younger infants and neonates.

Specific recommendations

Patient information

Patient information for specific ACE inhibitors is available from the NHS Website: Medicines A-Z, including their use in breastfeeding.

Further advice

Get in touch with the UK Drugs In Lactation Advisory Service (UKDILAS), our specialist breastfeeding medicines advice service, if:

  • the infant is premature or unwell
  • multiple medicines are being taken
  • the ACE inhibitor in question is not included in our advice
  • you need further advice.

About our recommendations

Recommendations are based on published evidence where available. However, evidence is generally very poor and limited, and can require professional interpretation. Assessments are often based on reviewing case reports which can be conflicting and lack detail.

If there is no published clinical evidence, assessments are based on: pharmacodynamic and pharmacokinetic principles, extrapolation from similar drugs, risk assessment of normal clinical use, expert advice, and unpublished data.

Simulated data are now increasingly being used due to the ethical difficulties around gathering good quality evidence in this area.


Full referencing is available on request.

Update history

  1. Amended links to updated recommendations
  1. Published

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