When mothers who are breastfeeding have to take a drug, they wonder whether they should stop breastfeeding. The answer depends on the following:
Some drugs, such as epinephrine, heparin, and insulin, do not pass into breast milk and are thus safe to take. Most drugs pass into breast milk but usually in tiny amounts. However, even in tiny amounts, some drugs can harm the baby.
Some drugs pass into breast milk, but the baby usually absorbs so little of them that they do not affect the baby. Examples are the antibiotics gentamicin, kanamycin, streptomycin, and tetracycline.
When possible, drugs should be taken immediately after breastfeeding or before the baby's longest period of sleep.
Drugs that are considered safe include most nonprescription (over-the-counter) drugs. Exceptions are antihistamines (commonly contained in cough and cold remedies, allergy drugs, motion sickness drugs, and sleep aids) and, if taken in large amounts for a long time, aspirin and other salicylates. Acetaminophen and ibuprofen, taken in usual doses, appear to be safe.
Drugs that are applied to the skin, eyes, or nose or that are inhaled are usually safe.
Most antihypertensive drugs do not cause significant problems in breastfed babies. Women may take beta-blockers during breastfeeding, but the baby should be checked regularly for possible side effects, such as a slow heart rate and low blood pressure.
Caffeine and theophylline do not harm breastfed babies but may make them irritable. The baby's heart and breathing rates may increase.
Even though some drugs are reportedly safe for breastfed babies, women who are breastfeeding should consult a health care practitioner before taking any drug, even an over-the-counter drug, or a medicinal herb. All drug labels should be checked to see whether they contain warnings against use during breastfeeding.
Some drugs require a doctor’s supervision during their use. Taking them safely while breastfeeding may require the following:
Most antianxiety drugs, antidepressants, and antipsychotic drugs require a doctor’s supervision, even though they are unlikely to cause significant problems in the baby. However, these drugs stay in the body a long time. During the first few months of life, babies may have difficulty eliminating the drugs, and the drugs may affect the baby’s nervous system. For example, the antianxiety drug diazepam (a benzodiazepine) causes lethargy, drowsiness, and weight loss in breastfed babies. Babies eliminate phenobarbital (an antiseizure drug and a barbiturate) slowly, so this drug may cause excessive drowsiness. Because of these effects, doctors reduce the dose of benzodiazepines and barbiturates as well as monitor their use by women who are breastfeeding.
Warfarin (a drug that prevents blood from clotting) can be taken if the baby is full-term and healthy. Warfarin does not appear to enter breast milk. People who take warfarin, including women who are breastfeeding, need to have blood tests done periodically to determine whether blood is clotting normally. Warfarin can cause a tendency to bruise or bleed.
Some drugs should not be taken by mothers who are breastfeeding. They include
Drugs that may suppress milk production include bromocriptine (used to treat Parkinson disease), estrogen, oral contraceptives that contain high-dose estrogen and a progestin, trazodone (an antidepressant), and levodopa.
If women who are breastfeeding must take a drug that may harm the baby, they must stop breastfeeding. But they can resume breastfeeding after they stop taking the drug. While taking the drug, women can maintain their milk supply by pumping breast milk, which is then discarded.
Women who are breastfeeding should consult their health care practitioner about all the drugs they are taking or about to start.
Women who smoke should not breastfeed within 2 hours of smoking and should never smoke in the presence of their baby whether they are breastfeeding or not. Smoking reduces milk production and interferes with normal weight gain in the baby.
Alcohol consumed in large amounts can make the baby drowsy and cause profuse sweating. The baby's length may not increase normally, and the baby may gain excess weight. Drinking up to 1 standard drink per day does not appear to harm the breastfeeding infant, especially if the woman waits at least 2 hours after a single drink before breastfeeding.