Is Bisoprolol safe while breastfeeding?

Summary of use during breastfeeding

Limited information indicates that a maternal dose of 5 mg daily produces low levels in milk, and some follow-up date indicate no adverse long-term effects on the breastfed infant. If bisoprolol is required by the mother, it is not a reason to discontinue breastfeeding. Other beta-blockers with more safety data may be preferred.

Effects on the breastfed infant

A woman was diagnosed with Cushing's disease during pregnancy. Postpartum she took metyrapone 250 mg 3 times daily, bisoprolol 10 mg twice daily, and captopril 12.5 mg twice daily. She breastfed her preterm infant about 50% milk and 50% formula. At 5 weeks postpartum, the infant's pediatric team found his growth and development to be appropriate.[3]

A prospective study followed 11 women who were taking bisoprolol in a median dose was 2.5 mg daily (range 1 to 5 mg) during breastfeeding (8 exclusively). The median age of the child at the time of follow-up was 49 (IRQ 25.5to 58.5) months. Adverse effects were reported among 2 infants: 1 with somnolence and 1 with poor weight gain. No abnormal results were found by Denver developmental scale. Median psychomotor development according to PEDsQL score total 97.5, psychosocial health 97.9 and physical health 100, all representing normal development.[4]

A prospective study of pregnant patients taking a beta-blocker asked mothers to complete a questionnaire about postpartum breastfeeding and any side effects in their breastfed infants. Four mothers reported taking bisoprolol in unreported dosages while breastfeeding. None reported any adverse reactions in their breastfed infants.[5]

A woman with peripartum cardiomyopathy and severe nonsustained ventricular tachycardia gave birth to twins. Bisoprolol 1.25 mg daily as well as amiodarone, febuxostat, imidapril, pitavastatin and vonoprazan were started postpartum. Breastfeeding began 39 days after birth when the daily intake of breastmilk was 160 mL for the first infant and 120 mL for the second, smaller infant. Breastmilk was mixed with infant formula and accounted for approximately one-quarter of their total daily milk intake. The mother breastfed in infants for approximately two months after starting breastfeeding and the infants had no bleeding tendency. At 3 years of age, both infants had a tendency toward obesity, but no other complications or developmental delay.[3]

Effects on milk supply

A study in 6 patients with hyperprolactinemia and galactorrhea found no changes in serum prolactin levels following beta-adrenergic blockade with propranolol.[6] Relevant published information on the effects of beta-blockade or bisoprolol during normal lactation was not found as of the revision date.

Levels in milk

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.[1] Accumulation of the drugs in the infant is related to the fraction excreted in urine. With 30% protein binding, 50% renal excretion and a moderately long half-life, bisoprolol presents a moderately high risk for accumulation in infants, especially neonates.

Maternal Levels. A woman was admitted at 36 weeks of pregnancy with complete heart block followed by ventricular tachycardia and fibrillation. After stabilization, she was given several doses of amiodarone and begun on bisoprolol 5 mg daily by mouth on day 9 of admission. She pumped her milk and provided 6 aliquots over a 6 day period (time with respect to dosage not stated). Bisoprolol was undetectable (<1 mcg/L) in all samples.[2]

Infant Levels. Relevant published information was not found as of the revision date.

Alternatives LactMed lists

• Propranolol
• Labetalol
• Metoprolol

Bisoprolol in pregnancy

LactMed covers breastfeeding only. For what the NHS and the US prescribing label say about pregnancy, see:

• Is bisoprolol safe in pregnancy and breastfeeding?