May 22 2022


This substance is related to well-identified adverse effects in some children breastfed, so it must be administered with great caution to nursing mothers. Atenolol is excreted in considerable amounts through breast milk, so it is preferable to use alternative medications, especially in the case of premature infants or during the neonatal period.

At usual doses, atenolol reaches a level in human milk from 0.025 to 2.1 mg / L. It is considered that an infant fed exclusively on breast milk would receive a percentage of the maternal dose between 5.7 and 19%.

A study on a small number of women taking beta-blockers showed a non-significant increase of adverse reactions. A baby whose mother took atenolol showed lethargy, although simultaneously she was taking another antihypertensive. A newborn with five days of life suffered cyanosis, bradycardia and hypothermia, while his mother was taking 100 mg/day of the drug. There have been other cases of infants without adverse reactions.

Warning of the manufacturer:

The concentration in breast milk is three times that in the blood. During lactation, have been found low levels of atenolol in children. However, beta-blocking effects in children can not be excluded in the long term.

It is recommended, whenever possible, maintain a time interval of 6 hours between administration of atenolol and breastfeeding. During this interval, the child may be fed by bottle.

When atenolol is administered during pregnancy and lactation should carefully weigh the advantages and disadvantages.