Can I take fluoxetine while pregnant or breastfeeding?

8.1 Pregnancy Pregnancy Category C — Fluoxetine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. All pregnancies have a background risk of birth defects, loss, or other adverse outcome regardless of drug exposure. Treatment of Pregnant Women during the First Trimester — There are no adequate and well-controlled clinical studies on the use of fluoxetine in pregnant women. Results of a number of published epidemiological studies assessing the risk of fluoxetine exposure during the first trimester of pregnancy have demonstrated inconsistent results. More than 10 cohort studies and case-control studies failed to demonstrate an increased risk for congenital malformations overall. However, one prospective cohort study conducted by the European Network of Teratology Information Services reported an increased risk of cardiovascular malformations in infants born to women (N = 253) exposed to fluoxetine during the first trimester of pregnancy compared to infants of women (N = 1,359) who were not exposed to fluoxetine. There was no specific pattern of cardiovascular malformations.

Prescribing label, section “8.1 Pregnancy” (opening excerpt): fluoxetine hydrochloride (oral), Bryant Ranch Prepack. Read the full section on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.

The average amount of drug in breastmilk is higher with fluoxetine than with most other SSRIs and the long-acting, active metabolite, norfluoxetine, is detectable in the serum of most breastfed infants during the first 2 months postpartum and in a few thereafter. Adverse effects such as colic, fussiness, and drowsiness have been reported in some breastfed infants. Decreased infant weight gain was found in one study, but not in others. No adverse effects on development have been found in infants followed for up to 5 years of age.

If fluoxetine is required by the mother, it is not a reason to discontinue breastfeeding. A safety scoring system finds fluoxetine use to be possible during breastfeeding,[1] although others do not recommend its use.[2] If the mother was taking fluoxetine during pregnancy or if other antidepressants have been ineffective, most experts recommend against changing medications during breastfeeding. Otherwise, agents with lower excretion into breastmilk may be preferred, especially while nursing a newborn or preterm infant. The breastfed infant should be monitored for behavioral side effects such as colic, agitation, irritability, poor feeding, and poor weight gain.

Mothers taking an SSRI during pregnancy and postpartum may have more difficulty breastfeeding, although this might be a reflection of their disease state.[3] These mothers may need additional breastfeeding support. Breastfed infants exposed to an SSRI during the third trimester of pregnancy are at risk for neonatal withdrawal syndrome consisting of hypoglycemia, tremors, tachycardia, or hypotonia, and might be at a greater risk of readmission due to jaundice.[4,5]

“Summary of Use during Lactation”, LactMed record “Fluoxetine” (LM323), quoted verbatim. Everything LactMed reports about Fluoxetine while breastfeeding.

Nursing Mothers Because fluoxetine is excreted in human milk, nursing while on fluoxetine is not recommended. In one breast-milk sample, the concentration of fluoxetine plus norfluoxetine was 70.4 ng/mL. The concentration in the mother's plasma was 295.0 ng/mL. No adverse effects on the infant were reported. In another case, an infant nursed by a mother on fluoxetine developed crying, sleep disturbance, vomiting, and watery stools. The infant's plasma drug levels were 340 ng/mL of fluoxetine and 208 ng/mL of norfluoxetine on the second day of feeding.

Prescribing label, section “Nursing Mothers”: fluoxetine hydrochloride (oral), Bryant Ranch Prepack. Label on DailyMed. Quoted verbatim; US labels are written for US prescribers and patients.