Drugs While Breastfeeding: Myths and Facts

When mothers who are breastfeeding have to take a drug, they wonder whether they should stop breastfeeding. The answer depends on the following:

•           How much of the drug passes into the milk

•           Whether the drug is absorbed by the baby

•           How the drug affects the baby

•           How much milk the baby consumes, which depends on the baby's age and the amount  

            of other foods and liquids in the baby's diet

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.

Drugs that are considered safe include most non-prescription (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.

Warfarin can be taken if the baby is full-term and healthy, but its use should be monitored.

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 adjusting the dose, limiting the length of time the drug is used, or timing when the drug is taken in relation to breastfeeding.

Most anti-anxiety 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 anti-anxiety drug diazepam (a benzodiazepine) causes lethargy, drowsiness, and weight loss in breastfed babies. Babies eliminate phenobarbital (an anticonvulsant 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.

Some drugs should not be taken by mothers who are breastfeeding. They include amphetamines, chemotherapy drugs (such as doxorubicin and methotrexate), chloramphenicol, ergotamine, lithium, radioactive drugs for diagnostic procedures, and illicit drugs such as cocaine, heroin, and phencyclidine (PCP). Drugs that may suppress milk production should not be taken. They include bromocriptine, estrogen, oral contraceptives that contain high-dose estrogen and a progestin, 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.

When possible, drugs should be taken immediately after breastfeeding or before the baby's longest period of sleep.

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.