Zonisamide-13C2,15N is
intended for use as an
internal standard for the quantification of zonisamide by GC- or LC-MS. Zonisamide (
T0267) is an antiepileptic agent.1 It selectively
inhibits the repeated fir
ing of sodium channels (IC50 = 2 μg/ml)
in mouse embryo sp
inal cord neurons and
inhibits spontaneous channel fir
ing when used at concentrations greater than 10 μg/ml.2
In rat cerebral cortex neurons, zonisamide (1-1,000 μM)
inhibits T-type calcium channels with a maximum reduction of 60% of the calcium current.3 Zonisamide (
T0267)
inhibits H. pylori recomb
inant carbonic anhydrase (CA) and the human CA isoforms I, II, and V with Ki values of 218, 56, 35, and 21 nM, respectively.4,5
In mice, it has anticonvulsant activity aga
inst maximal electroshock seizure (MES) and pentylenetetrazole-
induced maximal, but not m
inimal, seizures (ED50s = 19.6, 9.3, and >500 mg/kg, respectively). Zonisamide (
T0267) (40 mg/kg, p.o.) prevents MPTP-
induced decreases
in the levels of dopam
ine , but not homovanillic acid or dihydroxyphenyl acetic acid , and
increases MPTP-
induced decreases
in the dopam
ine turnover rate
in mouse striatum
in a model of Park
inson's disease.6 Formulations conta
ining zonisamide have been used
in the treatment of partial seizures
in adults with epilepsy.