Clinical Considerations 

Fetal/Neonatal Adverse Reaction — Neonates exposed during pregnancy to serotonin - norepinephrine reuptake inhibitors (SNRIs) or selective serotonin reuptake inhibitors (SSRIs) have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding which can arise immediately upon delivery. Reported clinical findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. These features are consistent with either a direct toxic effect of the SNRIs or SSRIs, or possibly, a drug discontinuation syndrome. It should be noted that, in some cases, the clinical picture is consistent with serotonin syndrome [see Warnings and Precautions (5.4)].

Data 

Animal Data — In animal reproduction studies, duloxetine has been shown to have adverse effects on embryo/fetal and postnatal development.

When duloxetine was administered orally to pregnant rats and rabbits during the period of organogenesis, there was no evidence of teratogenicity at doses up to 45 mg/kg/day (4 times the maximum recommended human dose (MRHD) of 120 mg/day on a mg/m2 basis, in rat; 7 times the MRHD in rabbit). However, fetal weights were decreased at this dose, with a no-effect dose of 10 mg/kg/day approximately equal to the MRHD in rats; 2 times the MRHD in rabbits).

When duloxetine was administered orally to pregnant rats throughout gestation and lactation, the survival of pups to 1 day postpartum and pup body weights at birth and during the lactation period were decreased at a dose of 30 mg/kg/day (2 times the MRHD); the no-effect dose was 10 mg/kg/day. Furthermore, behaviors consistent with increased reactivity, such as increased startle response to noise and decreased habituation of locomotor activity, were observed in pups following maternal exposure to 30 mg/kg/day. Post-weaning growth and reproductive performance of the progeny were not affected adversely by maternal duloxetine treatment.

8.3 Nursing Mothers
 
Risk Summary

Duloxetine is present in human milk. In a published study, lactating women who were weaning their infants were given duloxetine. At steady state, the concentration of duloxetine in breast milk was approximately 25% that of maternal plasma. The estimated daily infant dose was approximately 0.14% of the maternal dose. The developmental and health benefits of human milk feeding should be considered along with the mother's clinical need for duloxetine and any potential adverse effects on the milk-fed child from the drug or from the underlying maternal condition. Exercise caution when duloxetine is administered to a nursing woman.

Data

The disposition of duloxetine was studied in 6 lactating women who were at least 12 weeks postpartum and had elected to wean their infants. The women were given 40 mg of duloxetine twice daily for 3.5 days. The peak concentration measured in breast milk occurred at a median of 3 hours after the dose. The amount of duloxetine in breast milk was approximately 7 mcg/day while on that dose; the estimated daily infant dose was approximately 2 mcg