Anakinra and Breastfeeding

Summary of use during lactation

Anakinra is the pharmaceutical name for recombinant human 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. Many infants have been breastfed during maternal anakinra therapy, occasionally in conjunction with colchicine, with no obvious adverse effects or infections. Several international guidelines state that the drug is a low risk to the nursing infant and acceptable to use during breastfeeding.[1-3]

Drug levels in milk and infant serum

Maternal Levels. The concentration of IL-1Ra in colostrum in 88 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.[4] 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.[5] 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.[6] Among a cohort of 18 women with term pregnancies treated with anakinra for cryopyrin-associated periodic syndromes during pregnancy, 3 of the women breastfed their infants (extent not stated) for periods of <1 month, 3 months and 1 year. No adverse neonatal outcomes were reported.[7] In an international multicenter study of mothers exposed to interleukin-1 receptor antagonists, 10 babies were breastfed (extent not stated) by mothers receiving anakinra for up to 10 months. No infections or developmental abnormalities were reported.[8] Three of the cases had been reported previously in reference[7]. Of 5 women who took anakinra during pregnancy, two breastfed their infants while continuing to receive anakinra 100 mg daily. No serious infections were reported and development was normal.[9] A woman was treated with anakinra 100 mg subcutaneously once daily and oral colchicine 1 mg twice daily during pregnancy and postpartum for familial Mediterranean fever while she breastfed her infant (extent not stated). At 9 months of age, the infant’s development was within normal range. The routine vaccination schedule for the baby was being performed on time and there was no history of infection in the infant.[10] A woman with juvenile idiopathic arthritis was treated until 19 weeks of pregnancy with anakinra 100 mg daily by subcutaneous injection. It was discontinued for the duration of the pregnancy and then restarted 2 weeks after delivery while she partially breastfed her infant. No adverse reactions were reported.[11] A woman with recurrent pericarditis was treated with subcutaneous anakinra 100 mg once weekly beginning in the fifth month of pregnancy and continuing postpartum. She also took colchicine 0.5 mg daily. She delivered twins by cesarean section at 36 weeks of gestation and breastfed (extent not stated) her infants up to 18 months of age. No health problems were noted in the infants up to 18 months of age.[12] A woman with persistent colchicine-resistant pericarditis took anakinra throughout her pregnancy and at a dose of 100 mg twice weekly during breastfeeding (extent not stated) for 12 months and is still following this regimen. The child’s growth and development were normal with no reported infections or developmental abnormalities.[13] A case series reported 10 mothers from 4 European countries who were treated with anakinra for pericarditis who breastfed their infants (extent not stated), including one woman who breastfed two infants following 2 pregnancies. Doses ranged from 100 mg once a week to 100 mg once daily. Two of the women also took colchicine 1 mg daily. The infants had no reported infections or developmental abnormalities.[14] A French teratogen information service reviewed all patients exposed to anakinra during pregnancy over a 16-year period. In 3 retrospective and 5 prospective cases mothers breastfed while taking anakinra. No notable effects were reported in the infants. The extent of breastfeeding was not reported for most cases, but among the retrospectively followed cases, one mother breastfed for 12 months and one for 18 months. Follow-up was 22 and 51 months in two infants.[15]

Effects on lactation and breastmilk

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

Alternative drugs to consider

(Rheumatoid Arthritis) Adalimumab, Certolizumab Pegol, Etanercept, Infliximab, Tocilizumab

References

1. Sammaritano LR, Bermas BL, Chakravarty EE, et al. 2020 American College of Rheumatology Guideline for the Management of Reproductive Health in Rheumatic and Musculoskeletal Diseases. Arthritis Rheumatol 2020;72:529-5632090480 PubMed
2. Russell MD, Dey M, Flint J, et al. British Society for Rheumatology guideline on prescribing drugs in pregnancy and breastfeeding: Immunomodulatory anti-rheumatic drugs and corticosteroids. Rheumatology (Oxford) 2023;62:e48-e8836318966 PubMed
3. Rüegg L, Pluma A, Hamroun S, et al. EULAR recommendations for use of antirheumatic drugs in reproduction, pregnancy, and lactation: 2024 update. Ann Rheum Dis 2025;84:910-2640287311 PubMed
4. Buescher ES, Malinowska I. Soluble receptors and cytokine antagonists in human milk. Pediatr Res 1996;40:839-448947960 PubMed
5. Buescher ES, Hair PS. Human milk anti-inflammatory component contents during acute mastitis. Cell Immunol 2001;210:87-9511520075 PubMed
6. Berger CT, Recher M, Steiner U, et al. A patient's wish: Anakinra in pregnancy. Ann Rheum Dis 2009;68:1794-519822718 PubMed
7. Chang Z, Spong CY, Jesus AA, et al. Anakinra use during pregnancy in patients with cryopyrin-associated periodic syndromes (CAPS). Arthritis Rheumatol 2014;66:3227-3225223501 PubMed
8. Youngstein T, Hoffmann P, Gul A, et al. International multi-centre study of pregnancy outcomes with interleukin-1 inhibitors. Rheumatology (Oxford) 2017;56:2102-828968868 PubMed
9. Smith CJF, Chambers CD. Five successful pregnancies with antenatal anakinra exposure. Rheumatology (Oxford) 2018;57:1271-529660063 PubMed
10. Duman NC, Goren MZ, Karaalp A. Anakinra use during pregnancy and lactation: A case report. Reprod Toxicol 2019;88:139-40.doi:10.1016/j.reprotox.2019.05.029
11. Khokhar F, Pavlova V. Anakinra exposure in a pregnant patient with juvenile idiopathic arthritis: A case report. J Rheumatol 2019;46:830.doi:10.3899/jrheum.190333
12. Negro E, Costedoat-Chalumeau N, Nivuori M, et al. Anakinra during pregnancy in a difficult to treat case of recurrent pericarditis. Can J Cardiol 2023;39:1152-336306922 PubMed
13. Cerne Cercek A, Gomiscek Novak A, Trojner Bregar A, et al. Anakinra during pregnancy and lactation for corticosteroid-dependant colchicine-resistant recurrent pericarditis in a patient with neutralizing anti-interleukin-1 receptor antagonist antibodies: a case report. Eur Heart J Case Rep 2025;9:ytaf28040585191 PubMed
14. Trotta L, Mascolo R, Mardygan V, et al. Use of anakinra during pregnancy and breastfeeding in women with recurrent pericarditis: A case series. Eur J Obstet Gynecol Reprod Biol 2025;312:11455340609313 PubMed
15. Faure-Bardon V, Beghin D, Fautrel B, et al. Exposure during pregnancy to Il-1 targeted therapies and pregnancy, fetal and neonatal outcomes: A study from the French Teratology Information Service. Rheumatology (Oxford) 2025;64:6106-1340650931 PubMed