Zofran (Ondansetron) Safety During Breastfeeding
Zofran can be used during breastfeeding, though data on human milk transfer is limited and caution is warranted.
FDA Labeling Information
The FDA label for ondansetron explicitly states that it is not known whether ondansetron is present in human milk, and there are no data on effects on the breastfed infant or milk production 1. However, ondansetron has been demonstrated to be present in rat milk, and when a drug is present in animal milk, it is likely present in human milk 1.
- The FDA recommends that the developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for ondansetron and any potential adverse effects on the breastfed infant 1.
Clinical Approach to Medication Use While Breastfeeding
When prescribing any medication to a breastfeeding mother, several principles apply:
- Select medications with the lowest risk to the infant and dose before the infant's longest sleep interval 2.
- The amount of medication entering breast milk depends on maternal serum concentration and the drug's pharmacologic properties 2.
- Most medications appear in breast milk in only small amounts, and the dose transferred to the infant is typically small and does not lead to clinically significant effects 3.
- Take medication after breastfeeding, at the lowest effective dose, and for the shortest duration 4.
Monitoring Recommendations
If ondansetron is used during breastfeeding:
- Monitor the infant for unusual drowsiness, poor feeding, and irritability, as these can indicate adverse effects from medication exposure through breast milk 5.
- Single doses generally pose less risk than chronic use 5.
- Medications with short half-lives and poor oral bioavailability pose minimal risk to breastfed infants 5.
Alternative Considerations
For nausea and vomiting management in breastfeeding mothers, consider:
- Non-pharmacological approaches first when symptoms are mild 5.
- Other antiemetics may have more established safety data during lactation, though specific alternatives depend on the clinical indication 2, 3.
Important Caveats
- The lack of human data on ondansetron transfer into breast milk means the actual risk remains uncertain 1.
- In almost all instances, mothers should be advised to continue breastfeeding unless medications are absolutely contraindicated (such as anticancer agents or radioactive drugs) 3.
- Use current, authoritative resources like LactMed for the most up-to-date safety information 2.