Very limited data suggest breastmilk levels are likely to be low, but other medicine classes are preferred. Recommendations apply to full term, healthy infants.

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.


There is almost no published evidence of the use of any medicine in this class during breastfeeding.

If there are no other therapeutic options, angiotensin-II receptor antagonists can be used with caution during breastfeeding.  Candesartan, losartan or valsartan have the most favourable pharmacokinetics and would therefore be preferred.  However, given the very limited published evidence it would usually be preferable to choose a medicine from a different class which has more information supporting their use in breastfeeding.

See our advice on:


Milk levels of all angiotensin-II receptor antagonists are expected to be low, based on very limited published evidence and pharmacokinetic parameters.  They all have high plasma protein binding making it unlikely that they will be excreted into breastmilk to any great extent. Most have low to moderate oral bioavailability which limits the amount absorbed by the infant.

Candesartan, losartan or valsartan have the lowest oral bioavailability and shortest half-lives, making them preferred choices.  In addition, candesartan has limited published evidence supporting its use in breastfeeding.  Irbesartan and telmisartan have the longest half-lives and highest bioavailability and therefore are the least preferred options from this class.


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.

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

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

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 angiotensin-II receptor antagonists, 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 angiotensin-II receptor antagonists could affect kidney development. However, this has not been proven.

If an angiotensin-II receptor antagonists is the best therapeutic option, extra caution should be taken when breastfeeding younger infants and neonates.

Specific recommendations

Patient Information

Patient information for specific angiotensin-II receptor antagonists 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 unwell or premature
  • multiple medicines are being taken
  • the angiotensin-II receptor antagonist 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. Internal page links updated.
  1. Amended links to updated recommendations
  1. Minor typographical changes
  1. Published

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