Prescribing in Breastfeeding

All medicines transfer into breast milk.

The benefits of breastfeeding outweigh the risk of exposure to most medicines via breast milk.

In This Section

General Advice

For general advice, see Individualising Drug Therapy. Consider non-medicine measures first, and avoid all drug therapy if possible.
The infant benefits from breastfeeding (nutritional and immunological value) particularly in the first year of life.
The infant does not usually benefit from medicine exposure via breast milk.
The infant risk depends on the dose ingested via milk; and the medicine's oral availability and clearance in the infant.
The extent is less than drug transfer during pregnancy.
Monitor the infant for adverse effects of the medicine (e.g. failure to thrive, sedation, diarrhoea). Document any possible adverse effects, and reassess the infant risk and mother's benefit, depending on symptom and severity.
Dose after a feed where possible, to minimise medicine exposure. Concentrations in the milk usually follow concentrations in maternal plasma.
Medicine therapy rarely constitutes a reason to avoid breastfeeding in full-term healthy babies.
An infant dose < 10% of the maternal dose on a mg/kg basis – weight adjusted maternal dose (WAMD) – is considered "safe" for medicines that are not highly toxic.
Cytotoxic drugs with low WAMD are not considered "safe" (because they are highly toxic).
Consult when the infant is premature, has significant renal or hepatic disease or G6PD deficiency, or when the maternal dose is unusually high or poorly controlled (e.g. social drugs).
Consult readily with specialists in the area (e.g. Medicines Information 80900)

Medicines considered "safe" when breastfeeding full-term healthy babies


The following is a guide only and the list is not exhaustive.
Class	Examples of Individual Medicines
Analgesics	opioid analgesics* (short courses < 2 days): morphine, oxycodone, codeine, paracetamol, diclofenac, ibuprofen
Anticoagulants	enoxaparin, heparin, warfarin
Antiepileptic drugs*	carbamazepine, phenytoin, valproate sodium
Antidepressants*	SSRIs: citalopram, escitalopram, paroxetine, sertraline SNRIs: venlafaxine tricyclics: amitriptyline, nortriptyline
Antidiabetic	insulin, metformin
Antihistamines	cetirizine, loratadine
Antihypertensives	ACE inhibitors: enalapril, perindopril beta blockers: labetalol, metoprolol, propanolol calcium channel blockers: diltiazem, nifedipine methyldopa
Antimicrobials	betalactams: amoxicillin, flucloxacillin cephalosporins: cefalexin, ceftriaxone, cefazolin, cefuroxime, cefotaxime, cefepime, ceftazidime macrolides: azithromycin, clarithromycin, erythromycin, roxithromycin metronidazole (shorter courses – e.g. 400 to 600 mg BD for 7 to 10 days; avoid higher doses e.g. 2000 mg) nitrofurantoin trimethoprim, trimethoprim/sulfamethoxazole aciclovir, valaciclovir
Antipsychotics*	haloperidol, olanzapine, quetiapine, risperidone
Hypnotics*	short courses (< 2 days) of midazolam, temazepam, zopiclone
Cardiac glycoside	digoxin
Contraceptives	progestogen-only, combined oral contraceptives after 6 weeks post-partum
Corticosteroids (short courses)	prednisone (< 20 mg/day)
Gastrointestinal drugs	domperidone proton pump inhibitors: omeprazole, pantoprazole mesalazine

* For all, monitor infant for adverse effects (e.g. sedation, jitteriness, lethargy, poor feeding).

Medicines considered "unsafe" during breastfeeding

amiodarone
cytotoxic drugs
ergotamine
iodine-containing
medicines used during nuclear medicine exams
opioids (long courses > 2 days)
lithium (requires infant drug concentration monitoring)
retinoids (e.g. isotretinoin)
social drugs (e.g. alcohol, cannabis)

Topic Code: 93270