Download Antiepileptic Medication: Zonegran (zonisamide)

Antiepileptic Medication:
Zonegran (zonisamide)
General Information
•
Drug specific:
▬ Kidney stones
▬ Inability to sweat
▬ Painful rash on chest, back, and both
extremities: 85% of patients got a
rash in first 16 weeks.
▬ Decreased red and white blood cells.
•
Dose-related:
▬ Tiredness (20%)
▬ Dizziness (16%)
▬ Decreased appetite (16%)
▬ Feeling unsteady (17%)
▬ Irritability (12%)
•
Initiation: You may notice some doserelated side effects during the first couple of
weeks of treatment. Your body should get
used to the medication if you give it a
chance.
Zonisamide is one of the newer medications
approved for treatment of both partial and
generalized seizures. It was approved for use in
Japan in 1979 and in the US in 2003. It is used as
alone or as add-on therapy in adults and children.
How does it work?
Zonisamide helps to prevent seizures by blocking
sodium and calcium channels. It also increases the
production of GABA and slows down the
breakdown of GABA. GABA is an
neurotransmitter that blocks excitation of neurons.
Available forms
This drug offered as a generic medication. It is
available as a capsule in the following doses: 25
mg, 50 mg, and 100 mg.
You need to report any signs of drug specific
reactions to the doctor immediately. You may
be asked to stop the medication.
Drug basics
Zonisamide is chemically similar to sulfa. If you
are allergic to sulfa, you should not take
zonisamide.
Interactions
•
•
Co-medication with some phenytoin,
carbamezapine, phenobarbital decrease
zonisamide levels.
Dose may need to be reduced in kidney
failure.
After you take your dose, it takes about 2 to 4 hours
for the drug to have a maximum effect. You might
be more aware of dose related side effects at this
time if you have them. It takes about 50 to 70 hours
for half of the drug to be removed from your body.
Thirty to sixty percent of the drug binds to proteins
in your bloodstream. This part of the drug is
inactive. It is metabolized in the liver and is
excreted in the urine. There currently is no data on
use of zonisamide in pregnant women.
We are able to check a zonisamide level. There
isn’t an established range. It may not be necessary
to perform on a regular basis unless you are having
problems with side effects or increased seizure
activity. It does take about 4 days to get your
results.
Side Effects
If you are having difficulty with you medication,
please notify your doctor. You dose may be able to
be adjusted.
There are 3 different types of side effects.
Lab Monitoring
Final Note
References
• Shorvon, S. (2005). Handbook of epilepsy treatment, 2nd ed.
Malden, MA: Blackwell publishing:
Created by Diana Murray RN, CNS, MS, CNRN
Providence Brain Institute, Portland, Oregon
4/2008