ARK™ Zonisamide Assay

The ARK™ Zonisamide Assay is a homogeneous enzyme immunoassay for the quantitative determination of zonisamide in human serum on automated clinical chemistry analyzers. The measurements obtained are used in the monitoring of zonisamide levels to help ensure appropriate therapy.

Assay Characteristics

  • Excellent precision, even in trough concentrations
  • Fast and efficient routine monitoring for lacosamide
  • Liquid, ready-to-use reagents, calibrators and controls
  • Storage at 2-8°C
  • On-board stability for at least 60 days
  • Does not contain any harmful preservatives, only ≤ 0.09% sodium azide


Zonisamide (ZONEGRAN®, 1,2-Benzisoxazole-3-methanesulfonamide,) is an anti-convulsant drug approved for use as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.

A therapeutic range for zonisamide has not been well established. A reference range between 10 to 40 μg/mL has been suggested. In one study, a 50% reduction in seizures was observed at serum concentrations ranging from 7 to 40 mg/L. Some studies indicate an increased incidence of adverse effects at serum concentrations in excess of 30 mg/L. In general the relationship between these serum concentrations and clinical effect has not been well-defined, and considerable overlap in zonisamide concentrations has been observed between serum responders and non-responders as well as between serum levels associated with seizure control and adverse effects.