- SSRIs and their metabolites pass into breast milk in small amounts, generally below 7% of the weight adjusted maternal dose. Infant ingestion via milk is lowest for sertraline and fluvoxamine and highest for fluoxetine.
- SSRIs have relatively long half lives and there is a risk of drug accumulation, especially in the neonatal period when drug clearance values are significantly reduced.
- Because of shorter half lives, lower passage into milk and larger pools of data, paroxetine or sertraline are the preferred SSRIs for use in lactation.
- Premature infants and those with respiratory depression should not be exposed to SSRIs via breast milk.
- There is some overlap in symptoms between drug withdrawal after in utero exposure in the third trimester and exposure via breast milk, but sedation has been noted only in the latter circumstance.
- SSRIs should be used at the lowest effective dose and for the shortest possible time.
- If a woman has been successfully treated with a SSRI in pregnancy and needs to continue therapy after delivery, there is no need to change the drug, provided the infant is full term, healthy and can be adequately monitored.
- Infants exposed to SSRIs via milk should be monitored for sedation, poor feeding and behavioural effects.
- Co-therapy with other sedating agents is best avoided.
Acting Co-Director, West Midlands Medicines Information Service & UK Drugs in Lactation Advisory Service