Iguratimod Safety During Breastfeeding
Iguratimod should not be used during breastfeeding due to complete absence of safety data, and breastfeeding should be discontinued if this medication is required for maternal disease control.
Evidence Gap and Clinical Approach
Lack of Safety Data
- No published data exists regarding iguratimod transfer into breast milk or safety in breastfed infants 1
- The 2020 American College of Rheumatology guidelines specifically note that for newer small-molecule agents used in rheumatic diseases, there is "no available evidence regarding use or safety" during pregnancy or lactation 1
- Small-molecule drugs like iguratimod are likely to pass into breast milk due to their pharmacokinetic properties (low molecular weight, lipophilic nature) 1
Risk Assessment Framework
When evaluating any medication during breastfeeding, the decision must balance:
- Maternal disease control needs versus risks of untreated rheumatic disease 2
- Infant exposure risk through breast milk 2, 3
- Benefits of breastfeeding for both mother and infant 1
For iguratimod specifically:
- The complete absence of human lactation data makes risk quantification impossible 4, 2
- Small molecules typically achieve measurable concentrations in breast milk and may be orally bioavailable to the infant 1
- Unlike biologics (which have limited milk transfer due to large molecular size), small-molecule DMARDs pose theoretical but unquantified risk 1
Clinical Recommendations
If Iguratimod is Essential for Maternal Health:
- Discontinue breastfeeding if iguratimod cannot be substituted with a compatible alternative 1
- Consider switching to medications with established breastfeeding safety profiles (e.g., hydroxychloroquine, sulfasalazine, certain TNF inhibitors) 1
- Consult specialized resources like LactMed for the most current information on alternative agents 5
Alternative Approach:
- Prioritize medications with documented breastfeeding safety when treating rheumatic diseases postpartum 1
- The American College of Rheumatology emphasizes that "it is important to balance benefits of disease control with risk of infant exposure through breast milk" 1
- Most established DMARDs have sufficient safety data to guide clinical decisions, unlike iguratimod 6, 2
Important Caveats
- Few drugs are absolutely contraindicated during breastfeeding, but iguratimod falls into the category of "insufficient data to recommend" 4, 6, 7
- The principle that "only drugs that enter maternal bloodstream can transfer into breast milk" means systemically absorbed medications like iguratimod will reach the infant 8
- Premature or compromised infants face higher risk from medication exposure due to immature drug metabolism 1, 3
- Physicians should avoid advising breastfeeding cessation based on fear or expediency when safer alternatives exist 7, 2