Can you take penbutolol while breastfeeding?
What LactMed says
The National Library of Medicine’s own summary, quoted in full. We do not write a verdict of our own on this question, and we do not compress theirs into a label.
Penbutolol is not marketed in the United States. Based on its physicochemical properties, penbutolol appears to present a low-risk to the breastfed infant. Because there is no published experience with penbutolol during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.
Quoted from Penbutolol — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised August 15, 2024.
What LactMed would consider instead
LactMed ends this record by naming the drugs it would consider in place of penbutolol. Whether any of them fits depends on what you are treating — this is the database’s list, not a recommendation from us.
How much penbutolol gets into breastmilk
The excretion of beta-adrenergic blocking drugs into breastmilk is largely determined by their protein binding. Those with low binding are more extensively excreted into breastmilk. Accumulation of the drugs in the infant is related to the fraction excreted in urine. With 80 to 90% protein binding, 5% renal excretion and a moderate half-life, penbutolol presents a low risk for accumulation in infants.
Maternal Levels. Relevant published information was not found as of the revision date.
Infant Levels. Relevant published information was not found as of the revision date.
What has been seen in breastfed infants
Relevant published information on penbutolol was not found as of the revision date. A study of mothers taking beta-blockers during nursing found a numerically, but not statistically significant increased number of adverse reactions in those taking any beta-blocker. Although the ages of infants were matched to control infants, the ages of the affected infants were not stated. None of the mothers were taking penbutolol.
Effects on milk supply
Relevant published information on the effects of beta-blockade or penbutolol during normal lactation was not found as of the revision date. A study in 6 patients with hyperprolactinemia and galactorrhea found no changes in serum prolactin levels following beta-adrenergic blockade with propranolol.
Frequently asked questions
Can you take penbutolol while breastfeeding?
Penbutolol is not marketed in the United States. The full record is quoted on this page, and the decision is one to make with the person who prescribed it — LactMed itself states it is not a substitute for professional judgement.
What can I take instead of penbutolol while breastfeeding?
LactMed lists Propranolol, Labetalol, Metoprolol as alternate drugs to consider. That is the database's own list for this drug — whether any of them suits you depends on what you are treating.
Does penbutolol pass into breastmilk?
LactMed's measured drug levels for penbutolol are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking penbutolol?
LactMed does not frame its records that way — it reports measured drug levels in milk and what has been observed in breastfed infants, which is what this page quotes. "Pump and dump" advice for a specific drug and dose should come from your clinician or a pharmacist, not from a general rule.
More on penbutolol
LactMed states that the information it presents is not a substitute for professional judgement, and that you should consult your healthcare provider for breastfeeding advice related to your particular situation. Nothing on this page is medical advice.