Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Drug Use During Breastfeeding


Ravindu Gunatilake

, MD, Valley Perinatal Services;

Avinash S. Patil

, MD, University of Arizona College of Medicine

Last full review/revision Feb 2021| Content last modified Feb 2021

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.

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

Drugs That Are Relatively Safe During Breastfeeding

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 Drug therapy High blood pressure (hypertension) is persistently high pressure in the arteries. Often no cause for high blood pressure can be identified, but sometimes it occurs as a result of an underlying... read more Drug therapy 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.

Did You Know...

  • 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.

Drugs That Require a Doctor’s Supervision During Breastfeeding

Some drugs require a doctor’s supervision during their use. Taking them safely while breastfeeding may require the following:

  • Adjusting the dose

  • Limiting the length of time the drug is used

  • Timing when the drug is taken in relation to breastfeeding

Most antianxiety drugs Antianxiety and Sedative Drugs Antianxiety and sedative drugs are prescription drugs used to relieve anxiety and/or help with sleep, but their use can result in dependency and a substance use disorder. Using prescription... read more , antidepressants Drug therapy for depression A short discussion of prolonged grief disorder. Depression is a feeling of sadness and/or a decreased interest or pleasure in activities that becomes a disorder when it is intense enough to... read more , and antipsychotic drugs Antipsychotic drugs Schizophrenia is a mental disorder characterized by loss of contact with reality (psychosis), hallucinations (usually, hearing voices), firmly held false beliefs (delusions), abnormal thinking... read more 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.

Drugs That Should Not Be Taken While Breastfeeding

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.

Others also read
Test your knowledge
Breast Lumps
A breast lump (mass) is a thickening or bump that feels different from surrounding breast tissue. Which of the following statements about breast lumps is NOT correct?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID