Zonisamide (ZonigrenR) Zonisamide (ZNS) was synthesized as a benzisoxazole in 1974. It is chemically unrelated to any of the other AEDs. It is a small-ringed structure related to sulfonamide antibiotics with pH-dependent solubility in water. It had been approved by the US Food and Drug Administration (FDA) in March 2000 for the indication of partial … Continue reading ยากันชัก (Antiepileptic drug