Infant Exposure to Armodafinil Through Human Milk Following Maternal Use of Modafinil

Introduction: Narcolepsy, a condition adversely affecting psychological, social, and cognitive function, is more prevalent in females of childbearing age than the general population. Modafinil and armodafinil are central nervous system stimulants approved for treatment of narcolepsy. Infant exposure to these agents through human milk has not been investigated. Poor quality medication safety information during lactation is associated with early cessation of breastfeeding and suboptimal healthcare for the breastfeeding family. 

Main Issue: In this case study, we measured the concentration of armodafinil (the most active form of modafinil) in human milk and infant plasma to quantify infant exposure. 

Management: The participant was a 30-year-old primipara with narcolepsy, taking modafinil (300 mg morning, 100 mg noon) while breastfeeding her 6-week-old infant despite the paucity of safety information. Armodafinil concentrations were measured in eight serial human milk samples collected over a 26-hr period and in single maternal and infant plasma samples using ultra performance liquid chromatography - tandem mass spectrometry. The average concentration of armodafinil in human milk was 1.96 mg/L; the relative infant dose was 4.85%; the theoretical infant dose was 0.294 mg/kg/day. Maternal and infant plasma concentrations of armodafinil were 12.02 mg/L and 0.19 mg/L, respectively. The participant continued to exclusively breastfeed the infant, who had normal growth and development. 

Conclusion: Based on these findings, relatively small amounts of armodafinil pass into human milk, with consequent limited infant exposure. Consideration can be given to the use of modafinil or armodafinil during breastfeeding, provided the infant is monitored. Further studies are needed to confirm these findings.