Is Phenergan (promethazine) safe during breastfeeding?

Promethazine (Phenergan) Use During Breastfeeding

Promethazine (Phenergan) should be used with caution during breastfeeding, as it is not known whether it is excreted in human milk and could potentially cause adverse effects in nursing infants. 1

Safety Profile and Recommendations

• The FDA drug label specifically states: "It is not known whether promethazine HCl is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from promethazine hydrochloride tablets, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother." 1

• While the Association of Anaesthetists guideline mentions that prochlorperazine (a similar phenothiazine) has low oral bioavailability due to high first-pass metabolism and is compatible with breastfeeding, it does not specifically address promethazine. 2

Potential Concerns and Considerations

Sedation Risk

• Promethazine has significant sedative properties that could potentially affect a breastfed infant
• The drug can cause CNS depression and may increase, prolong, or intensify the sedative action of other central-nervous-system depressants 1

Alternative Options

• For nausea/vomiting during breastfeeding:

  • Metoclopramide is considered safe and may even increase milk supply 2
  • Domperidone has low levels in milk due to first-pass metabolism 2
  • Ondansetron has limited data but is likely to have low transfer into breast milk 2

• For allergies during breastfeeding:

  • All antihistamines are generally considered safe to use during breastfeeding, as minimal amounts are excreted in breast milk 3
  • Second-generation (non-sedating) antihistamines may be preferable to avoid sedation

Risk Minimization Strategies

If promethazine must be used:

• Use the lowest effective dose for the shortest duration possible
• Time administration immediately after breastfeeding to maximize clearance time before the next feeding 4
• Monitor the infant for unusual drowsiness or changes in feeding patterns
• Consider temporarily pumping and discarding breast milk during peak drug concentration periods

Important Considerations

• The benefits of breastfeeding are significant and generally outweigh minimal medication exposure risks 4
• When prescribing medications for a breastfeeding mother, those with the lowest risk to the infant should be selected 4
• Only a few drugs pose a clinically significant risk to breastfed babies, primarily antineoplastics, drugs of abuse, some anticonvulsants, ergot alkaloids, and radiopharmaceuticals 5

In conclusion, while promethazine is not absolutely contraindicated during breastfeeding, safer alternatives with better-established safety profiles should be considered first whenever possible.