How long after taking oral morphine (opioid analgesic) is a woman safe to breastfeed?

Breastfeeding After Oral Morphine

A woman can safely breastfeed immediately after taking a single dose of oral morphine, as soon as she has recovered sufficiently and is awake and alert. 1

Single Dose Administration

• No waiting period is required after a single dose of morphine before resuming breastfeeding 1
• Morphine is transferred to breast milk in small amounts, and a single dose would not be expected to cause detrimental effects to the infant 1
• The woman should simply wait until she has recovered from the procedure or is sufficiently awake and alert before nursing 1

Why Morphine is Preferred for Breastfeeding Women

• Morphine is recommended as the opioid of choice if strong analgesia is required in breastfeeding women 1
• Studies of morphine patient-controlled analgesia (PCA) following caesarean section showed that transfer of morphine and its active metabolite morphine-6-glucuronide into breast milk was low 1
• Breastfed babies showed no neurodevelopmental delays on day 3 following birth in these studies 1

Repeated Dosing Requires Monitoring

• If repeated doses of morphine are used, the infant should be monitored for signs of sedation and respiratory depression 1, 2
• This risk is more likely if there are also signs of excessive effects in the mother 1
• During long term treatment with morphine, the importance of uninterrupted breastfeeding should be assessed on an individual basis against the potential risk of adverse drug effects in the infant 3

Important Caveats

• Morphine has an active metabolite, morphine-6-glucuronide, which is more potent than the parent drug 1
• The lowest effective dose should be used for the shortest time possible when opioid analgesia is required 1, 2
• Infant exposure can be further reduced if breastfeeding is avoided at times of peak drug concentration in milk, which generally occurs 1-2 hours following oral medication 3, 4

Contrast with Other Opioids

Unlike codeine (which should be avoided due to unpredictable metabolism and risk of fatal infant toxicity) 1, 5 or oxycodone (which poses greater risk of infant sedation, especially at doses >30 mg/day) 1, morphine has a more predictable safety profile for breastfeeding women 1.