Is Zonisamide Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use Zonisamide? Is Zonisamide safe for nursing mother and child? Does Zonisamide extracts into breast milk? Does Zonisamide has any long term or short term side effects on infants? Can Zonisamide influence milk supply or can Zonisamide decrease milk supply in lactating mothers?

Zonisamide is excreted in breast milk in amounts that could be clinically significant, since the infant receives a relative dose well above 10% (Pack 2006, Crawford 2005, Tomson 2005, Shimoyama 1999, Kimura 1998). In spite of this high excretion in breast milk, infants who were breastfed by mothers taking zonisamide had no clinical problems (Shimoyama 1999) and their plasma zonisamide levels were only 15 to 17% of those measured in the mother (Kawada 2002, abstracts-P55 2011). Due to poor pharmacokinetics for breastfeeding with low protein binding and slow drug elimination (Jacob 2016) and the limited existing literature in relation to breastfeeding (Reimers 2014), it may be advisable to choose antiepileptics whose safety is better known (Hutchinson 2013, Davanzo 2013). If it is administered during breastfeeding, use the minimum effective dose (Reimers 2014) and monitor the infant's appetite, weight curve, psychomotor development, irritability, diarrhea, dehydration or acidosis, and it may be desirable to measure monthly plasma levels in the infant (Davanzo 2013, Pennell 2003). Some authors propose partial breastfeeding to decrease the dose that the infant receives through breast milk (Ando 2014).

Limited information indicates that maternal doses of zonisamide up to 400 mg daily produce high levels in milk and infant serum, but serum levels in neonates decrease during the first month of life while nursing. Although no adverse reactions have been reported in breastfed infants, the number of infants reported have been small. Alternative drugs are preferred, but if it must be given, monitor the infant for drowsiness, adequate weight gain, and developmental milestones, especially in younger or exclusively breastfed infants and when using combinations of anticonvulsant drugs. Some clinicians recommend that mothers taking zonisamide only partially breastfeed in order to reduce the exposure of the infant to the drug and to consider monitoring infants' serum zonisamide concentrations.[1]

A patient taking zonisamide 300 mg orally 3 times daily as well as other unspecified antipsychotics was followed at 0, 3, 14 and 30 days postpartum. Her infant exhibited no behavioral problems.[3] Two infants were breastfed postpartum by their mothers. One was exclusively breastfed for 9 days postpartum, then breastfed twice daily and supplemented with formula 7 to 8 times daily. The maternal zonisamide dose was 300 mg (6.2 mg/kg) daily. On day 34, the infant was healthy, had gained weight and had experienced no observable adverse effects. The second infant was partially breastfed by a mother taking zonisamide 100 mg (2.1 mg/kg) daily. No adverse reactions were noted in the infant during the first 2 weeks postpartum, at which time breastfeeding was discontinued because of a low milk supply.[1]