Is it safe to breastfeed while taking methylphenidate?

QUESTION: My patient has narcolepsy and is currently breastfeeding her 3-month-old infant. Lately she has had difficulties adjusting to caring for her baby, especially staying alert with the demands of breastfeeding. If she starts taking methylphenidate again, should I advise her to switch to formula?

ANSWER: Methylphenidate is excreted in breast milk only in small amounts, and to date there have been no reports of breastfed infants demonstrating any adverse effects. Based on the available data, methylphenidate appears to be compatible with breastfeeding; however, the long-term neurodevelopmental effects have not been adequately studied.