' Midlands Medicines
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UK Drugs in Lactation Advisory Service

What's New?

The database is currently being populated with data on common drugs used in lactation. Its aim is to include all drugs in the BNF.

  • Section on antihistamines added (03/06/12)

Risk classification

The compatibility of drugs with breastfeeding has been assessed through a combination of risk to the breastfed infant and the quality/volume of evidence available.  Drugs have been assigned to one of three categories which are defined as:


  • Serious adverse effects have been reported, or are considered possible, in a breastfed infant.
  • Lactation could be compromised because of an impact on milk production.


  • Minor and/or reversible adverse effects have been reported, or are considered possible, in breastfed infants, but which are not considered to pose an unacceptable risk to the infant.
  • Insufficient evidence of the amount of drug excreted into breast milk.
  • Insufficient evidence, or experience of use in practice, to guarantee safe use with breastfeeding.
  • Use of a medicine is conditional on risk-reducing actions being taken, e.g monitoring the infant, delaying breastfeeding after a maternal dose, using a lower-risk formulation etc.


  • Levels in milk are sufficiently low, or predicted to be low, because of the drug’s properties to present any risk to the infant.
  • Substantial clinical experience of the drug has not indicated any risks.
  • The medicine is in clinical use in young infants at doses significantly exceeding those which would be ingested through breast milk.


  • Use of this drug in breastfeeding mothers involves complex factors which can normally only be addressed by obtaining expert advice.