12:39 EST 27th January 2019 | BioPortfolio

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Zonisamide is an antiseizure drug chemically classified as a sulfonamide and unrelated to other antiseizure agents. The active ingredient is zonisamide, 1,2-benzisoxazole-3-methanesulfonamide. The molecular formula is C8H8N2O3S with a molecular weight of 212.23. Zonisamide is a white powder, pKa = 10.2, and is moderately soluble in water (0.8 mg/mL) and 0.1 N HCl (0.5 mg/mL).

The chemical structure is:


Zonisamide is supplied for oral administration as capsules containing 25 mg, 50 mg or 100 mg zonisamide, USP. Each capsule contains the labeled amount of zonisamide plus the following inactive ingredients: microcrystalline cellulose, hydrogenated vegetable oil, gelatin, and titanium dioxide.

In addition, individual empty hard gelatin capsule shell contains:

50 mg : Black iron oxide.

100 mg : FD&C Blue #1 and FD&C Red #40.

The imprinting ink contains black iron oxide, shellac glaze, propylene glycol and also contains either FD & C Blue No. 2, FD & C Red No. 40, FD & C Blue No. 1 and D & C Yellow No.10 or strong ammonia solution and potassium hydroxide.

Zonisamide is indicated as adjunctive therapy in the treatment of partial seizures in adults with epilepsy.

Zonisamide is contraindicated in patients who have demonstrated hypersensitivity to sulfonamides or zonisamide.

The abuse and dependence potential of zonisamide has not been evaluated in human studies (see WARNINGS, Cognitive/Neuropsychiatric Adverse Events subsection). In a series of animal studies, zonisamide did not demonstrate abuse liability and dependence potential. Monkeys did not self-administer zonisamide in a standard reinforcing paradigm. Rats exposed to zonisamide did not exhibit signs of physical dependence of the CNS-depressant type. Rats did not generalize the effects of diazepam to zonisamide in a standard discrimination paradigm after training, suggesting that zonisamide does not have abuse potential of the benzodiazepine-CNS depressant type.



Active Ingredients


Drugs and Medications [44 Associated Drugs and Medications listed on BioPortfolio]

Zonisamide [wockhardt limited]

Product Information Zonisamide Capsules Rx Only

Zonisamide [stat rx usa llc]


Zonisamide [zydus pharmaceuticals (usa) inc.]

Zonisamide Capsules

Zonisamide [cadila healthcare limited]

Zonisamide Capsules

Zonisamide [american health packaging]

Zonisamide Capsules USP 8423065/0618 Rx only

Clinical Trials [37 Associated Clinical Trials listed on BioPortfolio]

Fed Bioavailability Study of Zonisamide Capsules

The purpose of this study is to evaluate the relative bioavailability (rate and extent of absorption) of a test formulation of zonisamide capsules compared to the reference formulation, Zo...

Safety and Efficacy of Different Combinations of Zonisamide-CR Plus Bupropion-SR to Treat Uncomplicated Obesity

The purpose of this study is to determine which of seven combinations of Zonisamide CR and Bupropion SR gives the best weight loss and is safe and well tolerated for the treatment of obesi...

Fasting Bioavailability Study of Zonisamide Capsules

The purpose of this study is to evaluate and compare the relative bioavailability of a test formulation of zonisamide capsules to an equivalent dose of a reference formulation, Zonegran® ...

Efficacy and Safety of Adjunctive Zonisamide in Myoclonic Seizures Associated With Idiopathic Generalised Epilepsy

Zonisamide is already marketed for the treatment of partial seizures in epilepsy. This study is intended to provide evidence that zonisamide is safe and effective in the treatment of myocl...

Comparative Study of Zonisamide and Carbamazepine as an Initial Monotherapy: Efficacy and Safety Evaluation

The purpose of this study is to compare the efficacy and safety of zonisamide with carbamazepine and to determine the optimum dose of zonisamide in patients with epilepsy.

PubMed Articles [6 Associated PubMed Articles listed on BioPortfolio]

Clinical experience of using zonisamide in structural focal epilepsy in children with cerebral palsy.

To evaluate the efficacy and safety of zonisamide as an add-on therapy in structural focal epilepsy in children with cerebral palsy (CP).

Treatment of intractable resting tremor of spinocerebellar ataxia 42 with zonisamide.

Strategies of using the new antiepileptic drugs for epilepsy in adults.

The new antiepileptic drugs have not changed the basic pharmacological treatment principles of epilepsy, but they have given greater choice in focal and in generalized epilepsies as well. The new drug...

Major Congenital Malformations Associated With Exposure to Antiepileptic Drugs During Pregnancy.

Antiepileptic drugs (AEDs) are prescribed for approved and off-label indications that include epilepsy, bipolar disorder, and other neurologic and psychiatric disorders. The risk of major congenital m...

Effect of newer anti-epileptic drugs (AEDs) on the cognitive status in pentylenetetrazol induced seizures in a zebrafish model.

Epilepsy is marked by seizures that are a manifestation of excessive brain activity and is symptomatically treatable by anti-epileptic drugs (AEDs). Unfortunately, the older AEDs have many side effect...

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