Is codeine safe for a breastfeeding mother to use for pain management?

Codeine Should Not Be Used by Breastfeeding Mothers

Breastfeeding women should not take codeine due to unpredictable and potentially fatal infant toxicity, as recommended by the FDA, European Medicines Agency, and the Association of Anaesthetists. 1, 2

Why Codeine Is Contraindicated

Unpredictable Genetic Metabolism Creates Fatal Risk

• Codeine is a prodrug that requires conversion to morphine by the CYP2D6 enzyme system, which has extreme genetic variability that cannot be predicted without specialized testing 1, 2

• Ultrarapid metabolizers produce dangerously high morphine concentrations in breast milk, with documented cases of severe neonatal depression and death 1, 2

• The proportion of ultrarapid metabolizers varies dramatically by ethnicity: up to 28% in Middle Eastern/North African populations, up to 10% in Caucasians, and up to 1% in Asians 1, 2

• Even neonates of mothers who are extensive (normal) metabolizers face comparable risks of opioid poisoning as those of ultrarapid metabolizers 3

Pharmacokinetic Properties Amplify Risk

• Codeine's high lipophilicity and weak protein binding result in significant secretion into breast milk 1, 2

• The infant can further metabolize codeine after ingestion, compounding exposure 1

• Potentially toxic morphine concentrations can accumulate in the neonate within 4 days of repeated maternal codeine dosing 3

Regulatory Position Is Clear

• The US FDA and European Medicines Agency explicitly advise that breastfeeding women should not take codeine 1, 2

• The Association of Anaesthetists (2020) recommends against codeine use given the availability of safer alternative analgesics 1, 2

• While UK MHRA suggests codeine in moderation may be suitable for most women, this conflicts with the inability to predict which infants will be sensitive 1

If Codeine Has Already Been Taken

• Discard breast milk for 15 hours to allow full clearance from maternal plasma and prevent transfer to breast milk 1, 2

• Monitor the infant closely for signs of opioid toxicity including increased sleepiness, difficulty breastfeeding, respiratory depression, and decreased alertness 2, 4

Safer Alternative Analgesics for Breastfeeding

First-Line Options (Non-Opioid)

• Paracetamol (acetaminophen): The amount ingested via breast milk is significantly less than pediatric therapeutic doses 1

• Ibuprofen: Used extensively for postpartum pain and considered safe during breastfeeding 1, 5

• Diclofenac: Only small amounts detected in breast milk, widely used and considered safe 1

• Ketorolac: Low levels in breast milk without demonstrable adverse neonatal effects, compatible with breastfeeding 1, 5

If Weak Opioid Required

• Dihydrocodeine is preferred over codeine because its analgesic effect comes from the parent compound rather than requiring CYP2D6 metabolism, resulting in cleaner and more predictable metabolism 1, 2, 4

If Strong Opioid Required

• Morphine is the opioid of choice for breastfeeding women requiring strong analgesia 1, 2

• Single doses of morphine are not expected to cause detrimental infant effects 1

• With repeated morphine doses, monitor the infant for sedation and respiratory depression 1

Critical Pitfall to Avoid

The most dangerous error is assuming that "moderate" codeine doses are safe simply because they work well in the mother—even standard therapeutic doses can cause severe or fatal toxicity in infants of ultrarapid metabolizers, and there is no way to predict this without genetic testing that is not routinely available. 2, 3