Zonisamide (Zonegran) is used along with other medications to help control partial-onset seizures in people with epilepsy. It comes as an oral capsule that's available as a lower-cost generic. An oral suspension form of the medication is also available, but it's brand only and can be expensive.
Partial-onset seizures
Zonisamide (Zonegran) is an antiepileptic. This means it helps control seizures. It's not exactly clear how zonisamide (Zonegran) works, but it's thought to block the nerves in your brain from sending electrical signals that cause seizures.
Source:Â DailyMed
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
Discouragement
double vision
feeling sad or empty
irritability
lack of appetite
loss of interest or pleasure
mood or mental changes
shakiness or unsteady walking
tiredness
trouble with concentrating
trouble with sleeping
Less common
Agitation
bruising
delusions
hallucinations
large, flat blue or purplish patches on the skin
rash
Incidence not known
Blurred vision
change in near or distance vision
difficulty in focusing eyes
increase in frequency of seizures
swelling of the face
yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Abdominal or stomach pain
difficulty with memory
dizziness
double vision
headache
loss of appetite
restlessness
sleepiness
unusual drowsiness
unusual tiredness or weakness
Less common
Aching muscles or joints
acid or sour stomach
bad, unusual, or unpleasant taste in the mouth
belching
change in taste
chills
difficulty with speaking
difficulty with thinking
general ill feeling
headache
indigestion
mental slowness
nervousness
runny or stuffy nose
tingling, burning, or prickly feelings on the skin
uncontrolled, back and forth, or rolling eye movements
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Capsules available as a lower-cost generic
Can take once a day, so it's easier to remember to take
Can take with or without food
Can be a good add-on treatment to control seizures when other medications aren't working well enough
Comes as an oral suspension, which is an option for those who have problems swallowing
Can't be used by itself to control seizures
Only approved for people ages 16 years and older
Can take several weeks to get the full benefits of the medication
Not safe to take if you have a sulfa allergy
Might not be safe to take during pregnancy
You provider might instruct you to take zonisamide (Zonegran) once or twice daily. If you're experiencing a lot of dizziness or sleepiness, it might be safer to take this medication once daily in the evening time. This dosing schedule might not be appropriate for everyone, so talk to your provider about whether or not this is an option for you.
Don't drink alcohol or take other medications that can cause tiredness while taking zonisamide (Zonegran). This combination can worsen some of the side effects like sleepiness, dizziness, and lowered alertness, and it can also affect your breathing.
Don't stop taking zonisamide (Zonegran) without talking to your provider first. If you've been taking it for a while, your provider will lower your dose slowly over time. Stopping it too suddenly can cause seizures.
For the oral suspension (Zonisade brand)
Store the oral suspension at room temperature and shake well before each dose. The medication is only good for 30 days after opening the bottle. Throw away any leftover medication after 30 days.
Use an oral dosing syringe or medication cup to measure your dose in milliliters (mL). Household spoons should never be used to measure medications because they might not be accurate, even if you're specifically using a teaspoon or tablespoon. Talk to your pharmacist or provider if you don't have a proper dosing device.
Zonisamide (Zonegran) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Risk factors: Allergy to sulfonamides
Zonisamide (Zonegran) is a sulfonamide or sulfa medication. Don’t take zonisamide (Zonegran) if you're allergic to sulfa medications (e.g., Bactrim (sulfamethoxazole / trimethoprim), sulfasalazine (Azulfidine)), since you might have a severe allergic reaction. Get medical attention right away or go the emergency room if you notice a skin rash, swelling of the face or throat, or have difficulty breathing while taking zonisamide (Zonegran).
Although rare, zonisamide (Zonegran) can cause life-threatening skin reactions. In most cases, people start out with flu-like symptoms (such as fever, cough, sore throat, and fatigue) that develop into painful rashes and blisters on the body. Let your provider know if you notice any unusual rashes during treatment with zonisamide (Zonegran).
Some people taking zonisamide (Zonegran) have had serious and life-threatening allergic reactions affecting certain organs (such as the heart, kidneys, and liver). Symptoms of such allergic reactions can include fever, rash, severe muscle pain, swelling of the face, and yellowing of the skin or white part of the eyes. Let your provider know right away or get immediate medical attention if you notice any of these symptoms while taking zonisamide (Zonegran).
Risk factors: Under age 18 | Spending a lot of time in hot weather or environments
Zonisamide (Zonegran) treatment can make you less likely to sweat, which can make it harder for you to control your body temperature. This can put you at a higher risk for heat stroke, which can be life-threatening if not treated. The risk of this side effect is higher in younger people who take zonisamide (Zonegran). To prevent overheating, drink plenty of liquids, stay in the shade, and avoid staying in the sun too long if the weather is hot while taking zonisamide (Zonegran).
Some people taking zonisamide (Zonegran) experienced higher than normal pressure in their eyes. This can lead to blurred vision, eye pain, and eye redness. If left untreated, it can also lead to permanent loss of vision. Eye problems might begin within one month of starting treatment with zonisamide (Zonegran). Let your provider know if you start having eye problems while taking this medication.
Risk factors: Taking other medications for seizures
Zonisamide (Zonegran), like other medications used for seizures, can raise the risk of suicidal thoughts or behavior. Suicidal thoughts can happen as early as one week after starting this medication. If you or a loved one notices your mood worsening or thoughts of hurting yourself after you start taking zonisamide (Zonegran), talk to your provider right away.
Zonisamide (Zonegran) can make it harder for you to concentrate or remember things. It can also cause problems with speech, coordination, mood (new or worsening depression), and make you more sleepy. Be careful driving or doing anything that requires mental alertness while taking zonisamide (Zonegran).
Risk factors: History of kidney problems
Zonisamide (Zonegran) can raise your risk of getting kidney stones. Kidney stones can cause pain, but also sometimes fever, nausea, and blood in your urine. Usually, the stones pass on their own, but can require treatment at times. Zonisamide (Zonegran) can also affect how well your kidneys work, especially if you take the medication for a long time. If you have blood in your urine, changes in how often you urinate, swollen feet or ankles, excessive tiredness, or muscle cramping, talk to your provider. This could be a sign that zonisamide (Zonegran) is affecting your kidneys.
Risk factors: Diarrhea | Kidney problems | Severe lung problems | Ketogenic diet | Taking other medications that raise the acid level in your blood
In some rare cases, zonisamide (Zonegran) can raise the level of acid in your blood (metabolic acidosis). If not treated in time, it can cause kidney stones, or weaken your bones and make them likely to break. Metabolic acidosis can also lead to high levels of ammonia in the blood, which can affect the brain and cause you to become more tired, unable to concentrate, or vomit. Your provider might do regular blood tests to make sure there are no major changes in your blood acid level. If you develop metabolic acidosis during your treatment with zonisamide (Zonegran), your provider might decide that you need to stop taking the medication by slowly lowering the dose. In some cases, you might receive treatment for metabolic acidosis if your provider wants you to continue taking zonisamide (Zonegran). Contact your provider if you experience fast breathing, vomiting, or confusion during treatment, since these can be signs of high blood acid levels.
Talk to your provider before stopping zonisamide (Zonegran). Stopping zonisamide (Zonegran) suddenly can cause your seizures to come back or become worse. Your provider will work with you to lower your dose slowly over time so this doesn't happen.
Risk factors: Females of childbearing age
Based on animal studies, taking zonisamide (Zonegran) during pregnancy can put your unborn baby at risk for serious harm such as heart problems or even death. If you're a female who's able to become pregnant, it's recommended that you use a form of birth control while taking zonisamide (Zonegran) and for at least one month after your last dose of medication. Since this medication can cause serious birth defects, zonisamide (Zonegran) should only be used during pregnancy if the potential benefit outweighs the risk to the unborn baby.
This medication is available as capsules (Zonegran brand and generic) and an oral suspension (Zonisade brand). The typical dosing is the same for these formulations of zonisamide.
The typical starting dose of zonisamide (Zonegran) is 100 mg by mouth daily (taken all at once or split into two doses throughout the day). Your provider might raise your dose every two weeks based on your response to the medication. The typical dosing range is from 100 mg to 600 mg by mouth daily.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Allergy to sulfonamides
Seizures (partial seizures, tonic-clonic seizures)
Seizures of Lennox-Gastaut syndrome - immediate-release only
Bipolar disorder - immediate-release only
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