What is Zonisamide?

Zonisamide is used together with other medicines to control partial seizures (convulsions) in the treatment of epilepsy. This medicine is an anticonvulsant that works in the brain to stop seizures.

This medicine is available only with your doctor's prescription.

Take this medicine only as directed by your doctor to help your condition as much as possible. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine comes with a Medication Guide. Read and follow the instructions carefully. Ask your doctor if you have any questions.

Take the capsule with or without food. Swallow the capsule whole. Do not break, crush, or chew it.

Drink extra water every day with this medicine to help prevent kidney stones.

This medicine will be used together with other seizure medicines. Keep using all of your medicines unless your doctor tells you to stop.

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For oral dosage form (capsules):
  • For seizures:
    • Adults and children 16 years and older—At first, 100 milligrams (mg) once a day. Your doctor may adjust your dose as needed. However, the dose is usually not more than 400 mg per day.
    • Children younger than 16 years—Use and dose must be determined by the doctor.

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Appropriate studies have not been performed on the relationship of age to the effects of zonisamide in children younger than 16 years. Safety and efficacy have not been established.

Although appropriate studies on the relationship of age to the effects of zonisamide have not been performed in the geriatric population, geriatric-specific problems are not expected to limit the usefulness of zonisamide in the elderly. However, elderly patients are more likely to have age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving zonisamide.

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

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.

• Methenamine

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.

• Calcifediol
• Orlistat

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.

• Aminolevulinic Acid
• Ginkgo

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Blood or bone marrow problems (eg, agranulocytosis, aplastic anemia) or
• Depression, history of or
• Mental illness (eg, psychosis) or
• Metabolic acidosis (high acid in the blood)—Use with caution. May make these conditions worse.

• Breathing or lung problems, severe or
• Diarrhea or
• Ketogenic diet, history of—Use with caution. May cause side effects to become worse.

• Kidney disease or
• Liver disease—Use with caution. The effects may be increased because of slower removal of the medicine from the body.

It is very important that your doctor check your progress at regular visits to see if the medicine is working properly. Blood tests may be needed to check for unwanted effects.

This medicine may cause some people to be agitated, irritable, or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you or your caregiver notice any of these side effects, tell your doctor right away.

Contact your doctor right away if you develop a skin rash, fever, sore throat, sores in your mouth, easy bruising, severe muscle pain or weakness, or worsening of your seizures.

Check with your doctor right away if you have sudden back pain, abdominal or stomach pain, pain while urinating, or bloody or dark urine. These may be symptoms of kidney stones.

Serious skin reactions can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red skin lesions, often with a purple center, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness.

Zonisamide may cause serious allergic reactions that affect several body organs (eg, liver or kidneys). Check with your doctor right away if you have a fever, dark urine, headache, rash, stomach pain, swelling of the face, feet, or lower legs, swollen, painful, or tender lymph glands in the neck, armpit, or groin, trouble breathing, unusual tiredness, or yellow eyes or skin.

This medicine may make you sweat less, which causes your body temperature to increase. Use extra care not to become overheated during exercise or hot weather while you are taking this medicine. Overheating may result in heat stroke. Also, hot baths or saunas may make you dizzy or faint while you are taking this medicine.

Call your doctor right away if you have fast breathing, loss of appetite, fast, pounding, or uneven heartbeats, or unusual tiredness or weakness. These may be symptoms of a condition called metabolic acidosis.

Do not stop taking zonisamide without first checking with your doctor. Stopping the medicine suddenly may cause your seizures to return or to occur more often. Your doctor may want you to gradually reduce the amount of medicine you are taking before stopping it completely.

This medicine may cause some people to become dizzy, drowsy, or less alert than normal. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that make you drowsy or less alert). Some examples of CNS depressants are antihistamines, medicine for allergies or colds, sedatives, tranquilizers, sleeping medicine, prescription pain medicine, narcotics, medicine for seizures, muscle relaxants, or anesthetics, including some dental anesthetics. Check with your doctor or dentist before taking any of the above while you are taking this medicine.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines, and herbal or vitamin supplements.