zonisamide (Zonegran)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

What is zonisamide-oral, and how does it work (mechanism of action)?

Zonisamide is an anti-seizure medication. Zonisamide is primarily used to treat partial-seizures. Scientists do not known how exactly zonisamide works in the body. Zonisamide is presumed to work on the sodium and calcium channels in the brain cells where it controls electric-currents that are responsible for seizure activity.

The FDA approved zonisamide in March 2000.

What brand names are available for zonisamide-oral?


Is zonisamide-oral available as a generic drug?


Do I need a prescription for zonisamide-oral?


What are the side effects of zonisamide-oral?

Common side effects of zonisamide are:

Serious side effects of zonisamide include:

  • Psychiatric disorders such as schizophrenia
  • Seizures
  • Serious skin disorders such as Stevens-Johnson's syndrome or toxic epidermal necrolysis.

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What is the dosage for zonisamide-oral?

The recommended starting dose of zonisamide is 100 mg/day. Doses may be increased 100 mg/day every 2 weeks. The usual dosage varies from 100 to 600 mg/day, administered in 1 to 2 divided doses.

Safe and effective use of zonisamide is not established for children under the age of 16.

Which drugs or supplements interact with zonisamide-oral?

Zonisamide increases the risk of lactic acid build up when combined with metformin (Glucophage). If you experience sudden weakness, heavy breathing, and increased drowsiness, contact your healthcare professional immediately.

Orlistat (Xenical) should be used with caution with zonisamide because it lowers the beneficial effects of zonisamide and increases the chances of seizures. If you experience dizziness, drowsiness, difficulty walking, nausea, vomiting, and abnormal eye movements, contact your healthcare professional immediately.

Is zonisamide-oral safe to take if I'm pregnant or breastfeeding?

There are no adequate studies done on zonisamide to determine its safe and effective use in pregnant mothers.

It is not known whether zonisamide is excreted in breast milk. It should be used with caution in females who are nursing.

What else should I know about zonisamide-oral?

What preparations of zonisamide-oral are available?

Capsules: 25, 50, and 100 mg.

How should I keep zonisamide-oral stored?

Store zonisamide capsules between 20 C and 25 C (68 F and 77 F).

Medically reviewed by John P. Cunha, DO, FACOEP


FDA Prescribing Information.

Last Editorial Review: 5/16/2017

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Reviewed on 5/16/2017
Medically reviewed by John P. Cunha, DO, FACOEP


FDA Prescribing Information.

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