Recommendations apply to full-term and healthy infants. If the infant was born prematurely, is unwell, or the mother is taking multiple medicines, contact the UK Drugs in Lactation Advisory Service.
Breastfeeding can continue if the mother has COVID-19 infection.
Tocilizumab is considered compatible with breastfeeding, but should be used with caution and infant monitoring.
Available evidence for the use of tocilizumab during breastfeeding comes from other licensed indications which may use different dosing schedules and may have also involved prior exposure in pregnancy.
Breast milk levels and infant absorption
Tocilizumab is a very large molecule, so it will be very difficult for it to pass into breast milk.
There is very limited published evidence, but data show that levels in milk are negligible, with the maximum infant dose reported at around 0.007% of the weight-adjusted maternal dose.
As tocilizumab has negligible oral bioavailability, and is a protein molecule that will be mostly destroyed in the infant’s gastrointestinal tract, infant absorption via breast milk would be insignificant. Absorption may be increased slightly in the neonatal period due to increased gastrointestinal permeability, although this has not been proven.
Effects in infants
Adverse effects such as immunological reactions or severe infections have not been reported in any of the infants exposed to date, including one case report where the infant was followed for up to 12 months.
When infant serum levels have been sampled, these have been undetectable.
Sarilumab is considered compatible with breastfeeding, but should be used with caution and infant monitoring.
There is no published evidence regarding the use of sarilumab in breastfeeding. The risk assessment is based on the properties of sarilumab, and how similar medicines pass into breast milk.
Milk levels and infant absorption
Sarilumab is a very large molecule, so it will be very difficult for it to pass into breast milk.
As sarilumab has negligible oral bioavailability and is a protein molecule that will be mostly destroyed in the infant’s gastrointestinal tract, infant absorption via breast milk would be insignificant. Absorption may be increased slightly in the neonatal period due to increased gastrointestinal permeability , although this has not been proven.
Effects in infants
Adverse effects would not be expected to occur in the infant from exposure to sarilumab via breast milk.
Monitoring the infant
Although adverse effects are highly unlikely from tocilizumab or sarilumab exposure via breast milk, as a precaution monitor the infant for:
- feeding; the infant should be feeding well and continue to put on weight
- frequent infections
- unusual behaviour
Monitoring the infant will quickly pick up any potential issues, but usually further investigation is required before the cause can be identified. If any of these adverse effects occur, the mother should contact a healthcare professional for advice.
Live (attenuated) vaccination
Tocilizumab and sarilumab are immunosuppressive therapies. However, routine vaccinations, including live (attenuated) vaccinations, do not need to be withheld if an infant has been exposed to tocilizumab or sarilumab via breast milk. The risk of immunosuppression in the infant is negligible, and therefore:
- rotavirus vaccine can be given according to normal routine immunisation schedules
- BCG (Bacillus Calmette-Guérin) vaccine can be given if there is clinical need.
From the published evidence, some infants exposed to tocilizumab via breast milk were given live vaccination (rotavirus and BCG vaccines) with no adverse effects experienced.
If the infant was exposed to immunosuppressive biological therapy during pregnancy (including tocilizumab and sarilumab), specialist advice should be sought.
Medicines and Healthcare products Regulatory Agency (MHRA). Live attenuated vaccines: avoid use in those who are clinically immunosuppressed. Drug Safety Update (18 April 2016) [cited 27/09/21].
Public Health England. Immunisation Against Infectious Disease (Green Book). Chapter 6: Contraindications and special considerations (August 2017) [cited 27/09/21].
Royal College of Obstetrics and Gynaecology and Royal College of Midwives. Coronavirus (COVID-19) Infection in Pregnancy. Information for healthcare professionals, version 14 (25 August 2021) [cited 27/09/21].
Salonga A, Chay J, Nicholls D. A case series of patients with rheumatoid arthritis exposed to tocilizumab during pregnancy. Intern Med J. 2018;48:26–7.
Saito J, Yakuwa N, Kaneko K, et al. Tocilizumab during pregnancy and lactation: drug levels in maternal serum, cord blood, breast milk and infant serum. Rheumatology (Oxford). 2019 Aug 1;58(8):1505-1507.
Tada Y, Sakai M, Nakao Y, et al. Placental transfer of tocilizumab in a patient with rheumatoid arthritis. Rheumatology (Oxford). 2019;58:1694–5.
Saito J, Yakuwa N, Takai C, et al. Tocilizumab concentrations in maternal serum and breast milk during breastfeeding and a safety assessment in infants: a case study. Rheumatology (Oxford). 2018 Aug 1;57(8):1499-1501.
Moriyama M, Wada Y, Minamoto T, et al. Unexpectedly lower proportion of placental transferred tocilizumab relative to whole immunoglobulin G: a case report. Scand J Rheumatol. 2020 Mar;49(2):165-166
Nakajima K, Watanabe O, Mochizuki M, et al. Pregnancy outcomes after exposure to tocilizumab: A retrospective analysis of 61 patients in Japan. Mod Rheumatol. 2016 Sep;26(5):667-71.
Saito J, Yakuwa N, Kaneko K, et al. Clinical application of the dried milk spot method for measuring tocilizumab concentrations in the breast milk of patients with rheumatoid arthritis. Int J Rheum Dis. 2019;22:1130–7.
Saito J, Yakuwa N, Kaneko K, et al. Tocilizumab drug levels during pregnancy and lactation: A woman who discontinued tocilizumab therapy until the end of the first trimester and resumed it after birth. Obstet Med. Oct 29 2020.