Is fluoxetine medication compatible with breastfeeding of a premature infant (born in week 25)?/nTh

Fråga: Is fluoxetine medication compatible with breastfeeding of a premature infant (born in week 25)? The mother has been taking fluoxetine during the whole pregnancy, 20 mg/ day. The infant was born in a gestational age of 25 weeks and is taken care of by the neonatal department. The mother wants to breastfeed her baby and is also willing to change anti-depressive agent if necessary.

Sammanfattning: Fluoxetine and all other SSRIs are secreted into breast milk but to varying extent. Premature infants have a considerably lower capacity to eliminate drug due to lower metabolic capacity and decreased renal function. We conclude that one should not expose an already vulnerable premature infant to breast-milk containing fluoxetine. We advise the mother not to breast-feed her infant.

Svar: Infants born in the gestational age of 25 weeks has a considerably lower metabolic capacity than full-born infants (1,2). In addition they have an immature renal function. Thus, there is a risk of accumulation of drugs given to premature infants (3,4). There are no case-reports of premature infants given milk from mothers taking anti-depressants. Taking into account the possible decreased capacity to eliminate the drug and the lack of data from such cases, we believe that one should not expose an already vulnerable premature infant to fluoxetine.

Fluoxetine is secreted into breast-milk and the relative weight adjusted dose is approximately 8-9% (5). Fluoxetine in low concentrations has also been detected in blood from breast-feeding infants whose mothers is taking fluoxetine (6). There are case-reports of possible adverse drug reactions in breast-feeding infants whose mother is taking fluoxetine. However, other studies report no adverse effects in breast feeding infants (6). If SSRI-treatment is started post-partum fluoxetine might not be considered as the first drug of choice due to its pharmacokinetic properties (6).

Fluoxetine has a long half-life in adults, 2-7 days for fluoxetine and 4-15 days for the active metabolite norfluoxetine (7). It is considered to take 5 - 6 weeks after the medication is stopped until the drug is totally eliminated from the body (7). Even if the mother stops taking fluoxetine it might be secreted into the breast-milk for several weeks.

We advise the mother not to breast-feed her premature infant.