using oseltamivir and zanamivir during breastfeeding

Last edited 10/2023 and last reviewed 11/2023

Oseltamivir and zanamivir can be used during breastfeeding when clinically indicated (1)

• recommendations apply to full term, healthy infants only

Oseltamivir and zanamivir are used for the prevention and treatment of influenza:

• oseltamivir is the preferred choice during breastfeeding -infant monitoring is still required
  • limited data suggest that oseltamivir passes into breastmilk in negligible amounts
    
    
• is no published evidence for the use of zanamivir in breastfeeding, however infant exposure is expected to be insignificant
  
  
• zanamivir can be used by any route during breastfeeding when indicated
  
  
• treatment choice should be based on the clinical scenario with safety in breastfeeding a secondary consideration
  
  
• if the breastfed infant also needs direct treatment or prevention for influenza, the recommended dose of oseltamivir or zanamivir for infants should be given directly to the infant
  • is regardless of whether they are also exposed to oseltamivir or zanamivir via breast milk

• breastfeeding should continue as normal
• is no evidence that influenza can be transmitted via breast milk
• breast milk contains antibodies and other bioactive factors which can help protect the infant from influenza

• in order for breastfeeding to be facilitated it is important that mother and baby stay close together
  • however, consider the following to reduce the risk of the infant becoming infected:
    • wash hands for at least 20 seconds before touching the infant or any expressing equipment
    • avoid coughing or sneezing on the infant while breastfeeding
    • if used, clean breast pumps as recommended by the manufacturer after each use

Reference:

• NHS Specialist Pharmacy Service (October 2023). Using oseltamivir and zanamivir during breastfeeding