Which antihypertensive medication is contraindicated in lactating women?

Atenolol is identified as contraindicated in lactating women due to its potential effects on the breastfeeding infant. Atenolol can be excreted in breast milk, which raises concerns about potential side effects in a nursing infant, such as low heart rate and lethargy. While other medications in the same class, such as labetalol, metoprolol, and propranolol, can also pass into breast milk, they are generally considered safer and more acceptable for use during breastfeeding. Evidence suggests that the levels in breast milk for these alternatives are lower or have fewer adverse effects, making them preferable choices when managing hypertension in lactating women.