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

Tocilizumab is considered compatible with breastfeeding, but should be used with caution and infant monitoring.

Evidence

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

Sarilumab is considered compatible with breastfeeding, but should be used with caution and infant monitoring.

Evidence

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
• fever
• frequent infections
• diarrhoea
• 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.