Does Cosentyx Pass into Breast Milk?
Cosentyx (secukinumab), an IL-17A inhibitor for psoriasis and other conditions, is a monoclonal antibody with high molecular weight, limiting its transfer into breast milk. Studies show minimal to no detectable levels in milk after subcutaneous administration. A 2021 pharmacokinetic study in lactating women found secukinumab concentrations in breast milk were below the lower limit of quantification (less than 8.6 ng/mL) up to 42 days postpartum, even with standard dosing.1 This suggests negligible exposure to nursing infants.
Is It Safe for Breastfeeding Mothers?
Limited data indicate low risk. The antibody's structure and IgG1 subclass mean it is poorly absorbed by the infant gut if any traces reach it. No adverse effects were reported in the few exposed infants monitored. The American Academy of Pediatrics and LactMed database classify it as compatible with breastfeeding, with milk levels <0.1% of maternal dose.2 However, monitor infants for infections due to Cosentyx's immunosuppressive effects.
What Do Guidelines Say About Use During Lactation?
- FDA Labeling: Recommends considering benefits vs. risks; no contraindication but advises caution.4
- Manufacturer (Novartis): States data from 15 women showed no quantifiable secukinumab in milk; infant exposure unlikely to cause harm.5
- European Medicines Agency: Similar low-transfer findings; breastfeeding possible after weighing risks.6
How Does It Compare to Other Biologics?
Unlike smaller-molecule drugs (e.g., methotrexate, which concentrates in milk), Cosentyx behaves like other monoclonal antibodies:
| Drug | Milk Transfer | Infant Risk Notes |
|------|---------------|-------------------|
| Cosentyx (secukinumab) | Negligible (<0.1%) | Low; gut degradation likely |
| Humira (adalimumab) | Low (0.04-0.1%) | Compatible per AAP |
| Stelara (ustekinumab) | Very low | Preferred in IBD guidelines |
| Remicade (infliximab) | Minimal | Safe post-first trimester |
Adalimumab and ustekinumab have comparable profiles, often preferred in rheumatology for lactating patients.2
What Happens If an Infant Is Exposed?
Theoretical risks include mild immunosuppression, but no clinical cases of harm exist. Infant serum levels would be <<1% of maternal, per modeling. Pump-and-dump is unnecessary; timing feeds around doses isn't required due to slow clearance.3
Ongoing Research or Uncertainties
Data come from small cohorts (n<20); long-term infant outcomes unknown. Post-marketing surveillance continues. Consult a specialist for personalized advice, especially with preterm infants or maternal infections.
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