Is Symbicort Safe with Breastfeeding?
Yes, Symbicort (budesonide/formoterol) is safe to use while breastfeeding, with both components showing negligible infant exposure and explicit compatibility with lactation. 1
Evidence for Budesonide Safety During Breastfeeding
Budesonide is explicitly listed as "compatible" with breastfeeding in major international guidelines. 1 The European Respiratory Society/Thoracic Society of Australia and New Zealand task force directly addresses this in their comprehensive airways disease management statement, providing the highest level of guideline support for continued use during lactation.
Pharmacokinetic Data Supporting Safety
The most compelling evidence comes from direct measurement studies:
- Budesonide concentrations in breast milk are consistently lower than maternal plasma levels, with a mean milk-to-plasma ratio of only 0.46 2
- Estimated daily infant dose is only 0.3% of the maternal dose for both 200 mcg and 400 mcg twice-daily dosing 2
- Infant plasma concentrations are estimated to be 1/600th of maternal plasma levels, even assuming complete oral bioavailability in the infant 2
- Actual measured budesonide levels in infant blood samples were all below the limit of quantification, meaning undetectable 2
These pharmacokinetic findings demonstrate that budesonide transfers passively into breast milk but results in negligible systemic exposure to nursing infants. 2
Evidence for Formoterol Safety During Breastfeeding
Formoterol (the long-acting beta-agonist component) is classified as "probably safe" during breastfeeding with limited human data suggesting no risk or low risk. 1 While formoterol has less extensive lactation data than budesonide, the guideline framework supports its continued use, particularly when asthma control was achieved with this medication pre-pregnancy. 1
Clinical Context for LABAs
The European Respiratory Society notes that if a woman was already controlling symptoms with formoterol before pregnancy and breastfeeding, it is acceptable to continue with the same drug rather than switching. 1 This principle of therapeutic continuity applies directly to Symbicort use.
Risk-Benefit Analysis
The critical clinical principle is that risks of poorly controlled asthma far outweigh any theoretical risks from inhaled medications during lactation. 1 The guidelines emphasize that:
- Undertreated asthma resulting in maternal hypoxia has well-documented adverse effects 1
- Inhaled medications have been used for many years without documentation of adverse effects on infants through breast milk 1
- Modern inhaled corticosteroids including budesonide have negligible systemic absorption at recommended doses 1
Practical Recommendations
Continue Symbicort at the current maintenance dose without interruption during breastfeeding. 1, 2 Specifically:
- No need to pump and discard breast milk when using Symbicort at standard maintenance doses
- No timing restrictions around breastfeeding sessions are necessary given the negligible infant exposure 2
- Use the minimum effective dose to maintain asthma control, as with any medication during lactation 1
Common Pitfalls to Avoid
- Do not discontinue effective asthma therapy due to unfounded concerns about breastfeeding safety—this creates greater maternal and infant risk through poor asthma control 1
- Do not switch from Symbicort to another medication if asthma is well-controlled, as therapeutic continuity is preferred over switching to alternatives 1
- Do not use excessive doses—while standard maintenance doses (160-640 mcg budesonide daily) are safe, always use the lowest effective dose 1