Medications & Lactation

Analgesic / antipyretic

Compatibility

LactMed: amounts in milk are much less than doses given directly to infants; a preferred analgesic during breastfeeding.

Possible effects on infant / milk supply

Adverse effects in breastfed infants are rare; isolated reports of rash. No effect on milk supply.

NSAID

Compatibility

LactMed: very low milk levels and short half-life make it a preferred NSAID in nursing mothers.

Possible effects on infant / milk supply

No adverse infant effects reported at usual doses. Useful for mastitis-related inflammation and pain.

Opioid analgesic

Compatibility

LactMed: generally avoided; ultra-rapid metabolisers can produce high morphine levels in milk, with reported infant sedation and a fatality report.

Possible effects on infant / milk supply

Infant sedation, poor feeding, apnoea and respiratory depression, especially in the first weeks.

Safer alternatives to discuss

Paracetamol and ibuprofen first; if an opioid is needed, short courses of low-dose alternatives under medical supervision.

Opioid analgesic

Compatibility

LactMed: often preferred over codeine for short-term postpartum pain because of low oral bioavailability in the infant, but use the lowest effective dose for the shortest time.

Possible effects on infant / milk supply

Watch for infant drowsiness, difficulty feeding and breathing changes; higher risk with preterm infants.

Safer alternatives to discuss

Non-opioid analgesia where adequate.

Penicillin antibiotic

Compatibility

LactMed: milk levels are low; considered acceptable during breastfeeding.

Possible effects on infant / milk supply

Possible loose stools, thrush or rash in the infant; usually mild and self-limiting.

Cephalosporin antibiotic

Compatibility

LactMed: poor excretion into milk; acceptable in nursing mothers and commonly used for mastitis.

Possible effects on infant / milk supply

Occasional infant gut flora changes, diarrhoea or thrush.

Antistaphylococcal penicillin

Compatibility

LactMed: minimal amounts in milk; widely used for staphylococcal mastitis while breastfeeding continues.

Possible effects on infant / milk supply

Rare infant gastrointestinal upset or candidiasis.

Antibiotic / antiprotozoal

Compatibility

LactMed: infant doses via milk are below therapeutic infant doses; usually acceptable, though some clinicians limit exposure with high single doses.

Possible effects on infant / milk supply

Possible loose stools, oral thrush and a metallic taste that may make some infants fussy at the breast.

Antifungal

Compatibility

LactMed: milk levels are less than doses given directly to infants for thrush; acceptable in nursing mothers.

Possible effects on infant / milk supply

Adverse infant effects are uncommon; monitor liver-related symptoms only with prolonged courses.

Antiviral

Compatibility

LactMed: oral and topical use is acceptable; infant exposure is well below paediatric treatment doses.

Possible effects on infant / milk supply

No significant infant effects reported. Do not apply topical product where the baby's mouth will contact the skin.

SSRI antidepressant

Compatibility

LactMed: one of the preferred antidepressants during breastfeeding; milk levels are low and infant serum levels usually undetectable.

Possible effects on infant / milk supply

Occasional reports of infant irritability or sleep changes; monitor feeding and weight in newborns.

Safer alternatives to discuss

Paroxetine is another low-transfer option; discuss with your physician.

SSRI antidepressant

Compatibility

LactMed: usable, but the long half-life of the drug and its active metabolite gives higher infant exposure than some other SSRIs.

Possible effects on infant / milk supply

Reports of colic, fussiness, drowsiness and, rarely, poor weight gain in exclusively breastfed newborns.

Safer alternatives to discuss

Sertraline is often preferred for newly starting mothers.

Thyroid hormone

Compatibility

LactMed: a normal physiological constituent of milk; replacement doses are compatible with breastfeeding.

Possible effects on infant / milk supply

No adverse infant effects expected. Untreated hypothyroidism itself can reduce milk supply.

Antidiabetic

Compatibility

LactMed: milk levels are low and infant blood levels are usually undetectable; acceptable during breastfeeding.

Possible effects on infant / milk supply

No consistent adverse effects reported; monitor infant growth as routine.

ACE inhibitor (antihypertensive)

Compatibility

LactMed: milk levels are very low; considered acceptable, with more caution in preterm or very young newborns.

Possible effects on infant / milk supply

Monitor the infant for pallor or poor feeding in the first weeks; effects are rarely reported.

Safer alternatives to discuss

Labetalol and nifedipine are also widely used postpartum.

Beta blocker (antihypertensive)

Compatibility

LactMed: low milk levels; a preferred antihypertensive in nursing mothers.

Possible effects on infant / milk supply

Rarely, infant bradycardia or low blood pressure — watch for unusual sleepiness or poor feeding.

Safer alternatives to discuss

Atenolol is generally avoided because of higher milk transfer.

Decongestant

Compatibility

LactMed: single doses can measurably reduce milk production, especially in late lactation or established supply.

Possible effects on infant / milk supply

Possible reduced milk supply; occasional infant irritability or poor sleep.

Safer alternatives to discuss

Saline nasal sprays, steam, and topical nasal treatments discussed with your clinician.

Non-sedating antihistamine

Compatibility

LactMed: low milk levels and non-sedating; a preferred antihistamine during breastfeeding.

Possible effects on infant / milk supply

Infant drowsiness is unlikely; very large or repeated doses may theoretically affect supply.

Safer alternatives to discuss

Cetirizine is a similar option; sedating antihistamines are less preferred.

Proton pump inhibitor

Compatibility

LactMed: milk levels are low and the drug is degraded by infant stomach acid; acceptable during breastfeeding.

Possible effects on infant / milk supply

No adverse infant effects reported.

Anticoagulant

Compatibility

LactMed: not detected in milk and no bleeding effects reported in breastfed infants; acceptable with normal monitoring.

Possible effects on infant / milk supply

No effect on infant clotting expected in term, healthy babies.

Hormonal contraception

Compatibility

LactMed: oestrogen-containing contraceptives can reduce milk production, particularly if started before supply is well established.

Possible effects on infant / milk supply

Reduced milk volume and shorter breastfeeding duration in some mothers; no direct infant toxicity expected.

Safer alternatives to discuss

Progestogen-only pills, implants or intrauterine devices are usually preferred while breastfeeding.

Galactagogue / prokinetic

Compatibility

LactMed: increases prolactin and can modestly increase milk supply; milk levels are low, but maternal cardiac rhythm concerns and variable regulatory approval mean it is prescription-only.

Possible effects on infant / milk supply

Maternal QT prolongation risk and drug interactions; infant effects via milk are minimal.

Safer alternatives to discuss

Optimise milk removal, latch and pumping first; discuss any galactagogue with a physician.

Galactagogue / antiemetic

Compatibility

LactMed: may increase prolactin and supply in some mothers, but benefit is inconsistent and maternal side effects limit use to short courses.

Possible effects on infant / milk supply

Maternal depression, fatigue and extrapyramidal effects; infant intestinal discomfort has been reported rarely.

Safer alternatives to discuss

Non-pharmacological supply strategies first, under lactation-consultant guidance.

Cytotoxic / immunosuppressant

Compatibility

LactMed: low-dose weekly use may be acceptable in selected cases with expert advice, but antineoplastic (high-dose) regimens require withholding breastfeeding.

Possible effects on infant / milk supply

Potential bone marrow suppression and gastrointestinal toxicity in the infant; accumulates in infant tissues.

Safer alternatives to discuss

Discuss lactation-compatible immunosuppressants with rheumatology or oncology.

Radiopharmaceutical

Compatibility

LactMed: concentrates in breast tissue and milk; breastfeeding must be stopped, and therapy is usually delayed until lactation has ceased.

Possible effects on infant / milk supply

Risk of infant thyroid damage and radiation exposure.

Safer alternatives to discuss

Technetium-99m scans allow much shorter interruptions — ask nuclear medicine about options.

Social / recreational

Compatibility

LactMed: alcohol passes freely into milk; occasional single drinks are compatible if feeding is delayed about 2 hours per standard drink.

Possible effects on infant / milk supply

Regular or heavy use impairs let-down, reduces milk intake, and can cause infant drowsiness and disturbed sleep.

Safer alternatives to discuss

Pumping and discarding does not speed clearance — time is the only factor.