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 of drug transfer is less during breastfeeding than 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 to minimise medicine exposure with respect to feeds. 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 – relative infant dose (RID) – is considered "safe" for medicines that are not highly toxic.
Cytotoxic drugs with low RID 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	paracetamol, diclofenac, ibuprofen opioid analgesics* (short courses < 2 days): morphine, oxycodone, codeine^#
Anticoagulants	enoxaparin, heparin, warfarin
Antiepileptic drugs*	carbamazepine, lamotrigine, levetiracetam
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, propranolol calcium channel blockers: diltiazem, nifedipine methyldopa clonidine (if taken during pregnancy or under specialist care)
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; if using a 2000 mg dose, ideally avoid breastfeeding for 12 hours) 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 once breastfeeding has been established
Corticosteroids (short courses)	prednisone (≤ 40 mg/day)
Gastrointestinal drugs	domperidone proton pump inhibitors: omeprazole, pantoprazole mesalazine
Immunosuppressants	azathioprine, mercaptopurine, thioguanine hydroxychloroquine

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

^#Codeine use in breastfeeding is controversial. However, drug concentration data show that short courses are likely to be safe.

Medicines considered "unsafe" during breastfeeding

amiodarone
cytotoxic drugs
ergotamine
iodine-containing X-ray contrast media
medicines used during nuclear medicine exams
opioids (long courses > 2 days and/or doses > 20 mg oral morphine or equivalent)
lithium (requires infant drug concentration monitoring)
retinoids (e.g. isotretinoin)
social drugs (e.g. alcohol, cannabis)

Topic Code: 93270