Drug Levels and Effects:

Summary of Use during Lactation:

Anainra is the pharmaceutical name forrecombinanthuman interleukin-1 receptor antagonist (IL-1Ra). IL-1Ra is a normal component of human milk where it may play a role as an anti-inflammatory agent. No data exist on the excretion of anakinra into breastmilk after exogenous administration. One infant was reportedly breastfed during maternal anakinra therapy with no obvious adverse effects. However, long-term follow-up data on infants breastfed during maternal anakinra use are not available. An alternate drug may be preferred, especially while nursing a newborn or preterm infant.

Drug Levels:

Maternal Levels.

The concentration of IL-1Ra in colostrum in normal mothers was 672 ng/L, which was higher than the plasma concentration. Mature milk levels were lower than those in colostrum. Samples collected over a period of 2 to 6 months postpartum indicated that mothers continued to excrete IL-1Ra during this time.[1] Mothers with acute mastitis had slightly higher average levels of IL-1Ra than levels after recovery, but the median values were the same. The levels found in these mothers were the same as those of control mothers.[2]

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

A woman was receiving anakinra 100 mg daily for adult-onset Still's disease during pregnancy and lactation. Her breastfed (extent not stated) infant gained wight and appeared to have normal psychomotor development during an unspecified follow-up period.[3]

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.


1. Buescher ES, Malinowska I. Soluble receptors and cytokine antagonists in human milk. Pediatr Res. 1996;40:839-44. PMID:8947960
2. Buescher ES, Hair PS. Human milk anti-inflammatory component contents during acute mastitis. Cell Immunol. 2001;210:87-95. PMID:11520075
3. Berger CT, Recher M, Steiner U, Hauser TM. A patient's wish: anakinra in pregnancy. Ann Rheum Dis. 2009;68:1794-5. PMID:19822718

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Antirheumatic Agents\

  • Cytokines

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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