What is Zonisamide?

Zonisamide is an anticonvulsant medication a patient may take as an adjunct therapy to control seizures caused by epilepsy. This medication is available by prescription only, and a patient on zonisamide will need to see a doctor regularly to monitor the response to the medication and determine whether a dosage adjustment is needed. There is also a risk of developing acidosis while on this medication, making it necessary for the patient to undergo periodic tests to check on blood chemistry and identify dangerous changes as early as possible.

This medication is useful in the treatment of a range of seizure conditions. Research on zonisamide shows it also has applications in the management of migraine and Parkinson's disease and may be a useful mood stabilizing medication for patients with certain psychiatric conditions. As of 2011, the only approved use for the medication was as a seizure medication, with clinical trials for other applications underway to see if the medication could be useful for other conditions.

Patients on this medication can develop dizziness, drowsiness, irritability, and loss of appetite. Sometimes zonisamide has severe liver and kidney complications. Patients with abdominal pain, unexplained weight loss, and other severe side effects should discuss these with a doctor to determine the cause. It may be possible to step the dosage down to control seizures with less risk of side effects, or the person may need to change medications in cases where the patient cannot tolerate the drug.

Manufacturers produce zonisamide in the form of coated tablets. Several dosages are available to allow doctors to adjust dosage as a patient takes the medication. It can take several weeks to see if the medication is effective and the doctor may need to change the dose several times, usually starting low, to find the optimal dose for the patient. The tablets should be taken whole and cannot be crushed or split. People who have trouble swallowing pills can discuss options with a pharmacist.

As a maintenance medication, zonisamide must be taken on a regular schedule. Missing a dose can expose a patient to the risk of seizures. Patients can also be at risk of severe withdrawal if they attempt to stop taking the medication abruptly. If a change in drug is needed, the dosage should be tapered down to allow the patient to adjust. Patients worried about paying for zonisamide therapy may qualify for compassionate use medications for free from the manufacturer or could use samples from a doctor to cover periods when they have trouble buying the medication.