Opioid Use in Nursing Mothers
Opioids can be used safely in breastfeeding women when prescribed at the lowest effective dose for the shortest duration, with morphine and dihydrocodeine being the preferred agents, and mothers must monitor their infants for sedation, drowsiness, or respiratory depression. 1
Preferred Opioid Agents
Morphine is the opioid of choice for breastfeeding women requiring strong analgesia, as it transfers to breast milk in small amounts and has been specifically recommended by the Association of Anaesthetists. 1 Single doses cause minimal infant exposure, and even morphine patient-controlled analgesia following cesarean section showed low transfer with no neurodevelopmental delays in breastfed infants. 1
Dihydrocodeine is the preferred weak opioid due to its cleaner metabolism compared to codeine, which should be avoided entirely due to genetic variability in CYP2D6 metabolism that can lead to unpredictable morphine production. 1, 2
Safe Opioids Compatible with Breastfeeding
The following opioids are considered compatible with breastfeeding when used appropriately: 1
- Morphine (preferred strong opioid)
- Dihydrocodeine (preferred weak opioid)
- Fentanyl and alfentanil (single doses acceptable)
- Remifentanil (short half-life makes it suitable)
- Pethidine (compatible but not preferred)
Opioids Requiring Extra Caution
- Tramadol: Observe infant for unusual drowsiness 1
- Oxycodone: Greater risk of infant drowsiness at maternal doses >40 mg/day 1
- Codeine: Should be avoided due to CYP2D6 genetic polymorphism causing unpredictable conversion to morphine 1
Critical Monitoring Requirements
Infants must be observed for behavioral changes including sedation, drowsiness, respiratory depression, decreased alertness, and poor feeding. 1, 3 If these signs develop, mothers should immediately withhold breastfeeding and seek medical attention. 1
High-risk infants requiring extra caution: 1
- Preterm infants (highest risk)
- Neonates
- Infants <6 weeks of age (corrected for gestation)
- Any infant whose mother shows excessive sedation (indicator of potential infant effects)
Dosing Principles
Use the lowest effective dose for the shortest time possible, with multimodal analgesia incorporating paracetamol and NSAIDs to minimize opioid requirements. 1 Regional anesthesia and local anesthetic supplementation should be maximized to reduce systemic opioid needs. 1
For repeated opioid doses, infant monitoring becomes increasingly important as opioid effects accumulate with repeated maternal dosing. 1
Key Clinical Pitfalls to Avoid
Do not recommend "pump and dump" - expressing and discarding breast milk after opioid exposure is unnecessary, as the amounts transferred are generally minimal and compatible with breastfeeding. 1
Avoid co-sleeping when taking opioids, as maternal natural responsiveness to the infant may be inhibited. 1
Do not prescribe codeine to nursing mothers due to unpredictable metabolism - use morphine or dihydrocodeine instead. 1, 2
Monitor maternal sedation as an indicator of potential infant effects, since excessive maternal effects suggest higher drug levels that could affect the infant. 1
Alternative Pain Management Strategy
Prioritize non-opioid multimodal analgesia with paracetamol and NSAIDs (ibuprofen, diclofenac, naproxen, celecoxib, ketorolac), all of which are fully compatible with breastfeeding. 1 This approach minimizes opioid exposure while maintaining adequate pain control.