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Medications That Affect Breast Milk
Breastfeeding provides essential nutrients and immunity-boosting benefits to infants. However, many breastfeeding moms worry about medications that affect breast milk, and how they might impact their milk supply or their baby’s health. Some drugs are safe, while others may reduce milk production or even pose risks to your little one.
How Medications Transfer into Breast Milk
Understanding Drug Transfer to Breast Milk
- According to the MSD Manual (2024) ,Not all medications pass into breast milk, and those that do usually appear in small amounts.
- According to the Hale, T. W 2024 ,Most drugs enter breast milk through passive diffusion, meaning they pass from the maternal bloodstream into milk due to concentration differences.
Factors Affecting Drug Transfer
Several factors influence how much of a drug transfers into milk:
- Molecular size: Larger molecules (e.g., insulin, heparin) do not easily pass into breast milk.
- Lipophilicity (Fat Solubility): Fat-soluble drugs (e.g., diazepam) accumulate in breast milk more than water-soluble drugs.
- Protein Binding: Drugs that bind strongly to proteins (e.g., warfarin) are less likely to enter milk.
- Milk-to-Plasma (M/P) Ratio: A higher ratio means more of the drug is present in breast milk.
- Dosage & frequency: Higher doses and frequent use increase the drug’s presence in milk.
- Baby’s age: Newborns process drugs more slowly than older infants.
- Mother’s metabolism: Fast metabolism may reduce the time a drug stays in the system.
- Breast milk pH: The pH of breast milk can affect the transfer of medications.
- Medication timing: Taking medications immediately after breastfeeding can minimize the amount that passes into breast milk.
According to a study published in Australian Prescriber (2016), most medications transfer at levels below 10% of the maternal dose, making them relatively safe for breastfeeding. However, some drugs require caution.
Common Medications That Affect Breast Milk
1. Medications That Reduce Milk Supply
Some medications interfere with prolactin, the hormone responsible for milk production. If you’re struggling with supply, avoiding these medications may help:
- Decongestants (Pseudoephedrine, Phenylephrine) : According to the Drugs and Lactation Database (LactMed®) ,Pseudoephedrine & Phenylephrine found in cold and flu medications, these can lower prolactin levels by up to 24% after a single dose .
- Hormonal Birth Control (Oestrogen-containing contraceptives) – According to the World Health Organization (WHO) ,High-dose oestrogen can significantly reduce milk production .
- Diuretics (Furosemide, Hydrochlorothiazide) : According to the WHO (2022) ,diuretics are used for high blood pressure, these drugs increase urine output, potentially leading to dehydration and reduced milk supply .
- Dopamine Agonists (Cabergoline, Bromocriptine) : According to the StatPearls (2023) Specifically used to suppress lactation by reducing prolactin levels .
- Antihistamines: According to the American Academy of Family Physicians (2022 ),Some antihistamines, such as diphenhydramine (Benadryl) and cetirizine (Zyrtec), may also affect milk supply.
- Ergotamines : According to the MSD Manual (2024) ,Ergotamines are used for migraines, these can suppress lactation.
- Attention-deficit/hyperactivity disorder (ADHD ) medications: According to the Anderson ( 2021) ,Amphetamines can lower prolactin levels in the blood and have been detected in higher concentrations in breast milk and infant blood.
- Herbal Supplements: According to the Drugs and Lactation Database (LactMed®) ,Some herbs like sage, peppermint, and parsley in therapeutic amounts may reduce milk supply.
2. Medications That Can Harm the Baby
Certain drugs can accumulate in breast milk and affect the baby’s health:
- Painkillers (Codeine, Tramadol) : According to the FDA (2022),These opioids can cause drowsiness and, in rare cases, respiratory depression in infants .
- Antidepressants (Fluoxetine, Citalopram) : According to the Drugs and Lactation Database (LactMed®) (2023) ,While generally safe, fluoxetine has a long half-life and can accumulate in a baby’s system .
- Antibiotics (Metronidazole, Tetracyclines) : According to the American Academy of Family Physicians (2022 ) ,Metronidazole may alter infant gut flora, while tetracyclines can affect bone growth .
- Mood Stabilizers (Lithium, Valproate): According to the International Journal of Bipolar Disorders (2018) ,Lithium levels in breast milk can be as high as 40% of the maternal dose, making monitoring essential .
3. Medications Considered Safe for Breastfeeding
Thankfully, many common medications are compatible with breastfeeding:
- Paracetamol (Acetaminophen) : According to the Hale, T. W (2024) , Paracetamol is considered the safest painkiller for breastfeeding mums .
- Ibuprofen : According to the NHS & Studies in Pediatric Drugs, Ibuprofen has shown minimal transfer into breast milk and no known effects on infants .
- Loratadine (Antihistamines) According to the WHO (2022) , Non-drowsy antihistamines like loratadine that don’t significantly affect milk supply .
- Certain Antibiotics (Penicillins, Cephalosporins) : According to the American Academy of Family Physicians (2022),Safe when used in standard doses.
- Hormonal contraceptives: According to the Hale, T. W (2024), Progestin-only pills, like the mini-pill, are a safer option for nursing mothers.
- Antidepressants: According to the US Pharmacist (2021 ) ,citalopram, escitalopram, and sertraline, are considered compatible with breastfeeding.
- Galactagogues (supply boosters): According to the Drugs and Lactation Database (LactMed®) (2025), fenugreek, blessed thistle, and goat’s rue are traditionally used as galactagogues ( milk supply boosters).
4. Medications That Change Milk Composition
Some substances can alter the composition of breast milk, which might affect your baby.
Herbal Supplements, Vitamins, and Lifestyle Factors
Caffeine: According to the MSD Manual (2024),Moderate amounts are safe, but excessive consumption can affect infant sleep patterns.
Herbal Supplements: According to the American Academy of Family Physicians (2022 ),Their safety during breastfeeding is not well established, so it’s best to avoid them unless advised by a healthcare provider.
High Doses of Vitamins: According to the WHO (2022) ,Excessive intake of Vitamins in breastfeeding mom can be harmful, so stick to recommended doses.
Alcohol and Nicotine: According to the MSD Manual (2024) ,Both can affect milk composition and infant health. Alcohol in moderation (up to one standard drink per day) is generally safe if you wait a couple of hours before breastfeeding.
Safe Alternatives & Risk Management
How to Minimize Medication Risks While Breastfeeding
- Consult a healthcare provider before taking any medication.
- Choose breastfeeding-safe alternatives where possible.
- Time your medication intake to minimize infant exposure (e.g., taking it immediately after nursing).
- Monitor your baby for changes like drowsiness, feeding difficulties, or irritability.
- Use reliable resources like LactMed, the InfantRisk Center, and Hale’s Medications & Mothers’ Milk for updated drug safety information.
FAQs :Medications That Affect Breast Milk
Can I take cold and flu medication while breastfeeding?
Yes, but avoid pseudoephedrine, as it may reduce milk supply. Opt for saline nasal sprays or breastfeeding-safe antihistamines like loratadine.
How long does medication stay in breast milk?
This depends on the drug’s half-life, dose, and maternal metabolism. Most medications clear within a few hours, but some, like fluoxetine, can accumulate over time.
Are herbal supplements safer than pharmaceuticals?
Not necessarily. Some herbs (e.g., peppermint, sage) can lower milk supply, and others (e.g., ginseng) may be unsafe for infants. Always check with a qualified professional.
Can I take pain relievers while breastfeeding?
Yes, acetaminophen and ibuprofen are generally considered safe for breastfeeding mothers.
Can I take antihistamines while breastfeeding?
Diphenhydramine (Benadryl) can cause drowsiness in infants and decrease milk supply. Consult your healthcare provider before taking any antihistamines.
Can I take antibiotics while breastfeeding?
Most antibiotics are considered safe for breastfeeding mothers, but some, like tetracycline, can affect tooth and bone development in infants. Consult your healthcare provider before taking any antibiotics.
What is “pumping and dumping”?
Pumping and dumping involves expressing breast milk and discarding it to avoid exposing your baby to medication. This is typically recommended for short-term use of medications that are not considered safe during breastfeeding.
Last Updated on March 19, 2025 by imramediceena@gmail.com
Pharmacist with over 15 years of experience in both community and industrial pharmacy.
His expertise spans various fields, including pharmaceutical research and development, formulation development, and controlled drug delivery systems. He has a strong background in pharmaceutics, focusing on the creation of effective drug formulations and delivery methods.
Throughout his career, Imran has contributed significantly to the pharmaceutical field.
He is a co-author of the article titled "Biological Screening of the Plant Medicago denticulata for Cytotoxic, Phytotoxic, Antimicrobial and Antifungal Effects,"
Additionally, he co-authored "Formulation and Permeation Kinetic Studies of Flurbiprofen Gel,"
Furthermore, he is the author of "Controlled-release low density effervescent floating matrix tablets of risperidone: Development, optimization, in vitro-in vivo evaluation in healthy human volunteers and determination of dissolution equivalency." This work underscores his focus on innovative drug delivery systems that improve patient compliance and therapeutic outcomes.
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