title: Two nursing mothers treated with zonisamide: Should breast-feeding be avoided?
abstract: Zonisamide, an antiepileptic drug, is excreted into breast milk, but information regarding the safety of breast-feeding while using this drug is limited. We present the cases of two nursing mothers, taking 300 and 100 mg/day zonisamide. At 5 days after delivery, the milk concentrations and relative infant doses of the drug were 18.0 and 5.1 μg/mL, and 44 and 36%, respectively. In the first case, the mother fed colostrum and continued partial breast-feeding thus reducing the relative infant dose to 8%. The neonatal serum concentration of zonisamide declined to below the limit of detection at day 34 after birth. In the second case, the mother breast-fed partially until 2 weeks postpartum. No adverse effect was observed in the infants. These findings suggest that mothers taking zonisamide should not breast-feed exclusively, but may not have to avoid partial breast-feeding, with significant caution regarding adverse effects in infants.
authors.affiliation: Division of Clinical Pharmacology, Department of Pharmacology, Jichi Medical University, Shimotsuke, Tochigi, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ando
authors.forename: Shigeki
authors.initials: S
authors.lastname: Matsubara
authors.forename: Asako
authors.initials: A
authors.lastname: Oi
authors.forename: Rie
authors.initials: R
authors.lastname: Usui
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Suzuki
authors.forename: Akio
authors.initials: A
authors.lastname: Fujimura
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects / Q000032:analysis / Q000493:pharmacokinetics* / Q000600:supply & distribution; D001682:Biological Availability; D001942:Breast Feeding / Q000009:adverse effects*; D002657:Child Development / Q000187:drug effects; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy / Q000378:metabolism; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D007555:Isoxazoles / Q000009:adverse effects / Q000032:analysis / Q000493:pharmacokinetics* / Q000627:therapeutic use; D007774:Lactation / Q000097:blood / Q000378:metabolism*; D008297:Male; D008895:Milk, Human / Q000737:chemistry* / Q000378:metabolism; D000078305:Zonisamide
chemical_list: D000927:Anticonvulsants; D007555:Isoxazoles; D000078305:Zonisamide
keywords: antiepileptic drug; breast milk; breast-feeding; relative infant dose; zonisamide