What is Zonegran?
Zonegran is a medicine that contains the active substance zonisamide. It is available in white (25 mg), white and gray (50 mg), and white and red (100 mg) capsules.
What is Zonegran used for?
Zonegran is indicated as add-on therapy in the treatment of adult patients with partial seizures (seizures that originate in a specific part of the brain). It can be used in patients with or without secondary generalization (secondary generalization occurs when hyperactivity subsequently expands to the entire brain area).
The medicine can only be obtained with a prescription.
How is Zonegran used?
Zonegran must be added to existing therapy. The recommended starting dose is 25 mg twice a day, to be taken with or without food. After one week the dose can be increased up to 100 mg per day and thereafter the dose can be increased at weekly intervals in increments of up to 100 mg, depending on the patient's response. Once the most appropriate dosage has been established, Zonegran can be administered once or twice a day. Doses of 300 to 500 mg per day have been shown to be effective, but lower dosages may be sufficient for some patients. The maximum daily dose is 500 mg.
In patients with liver or kidney disorders or in people taking certain other medicines the dose may need to be increased less frequently. Zonegran should be used with caution in elderly patients and in those with kidney disorders. Use of the medicine in patients with severe hepatic impairment is not recommended. The dose should be gradually reduced before stopping Zonegran.
For more information, see the Summary of Product Characteristics, also included in the EPAR.
How does Zonegran work?
The active substance in Zonegran, zonisamide, is an antiepileptic. Seizures are caused by "abnormal electrical activity in the brain. Zonisamide works by blocking certain pores located on the surface of nerve cells called sodium channels and calcium channels. These channels transmit electrical impulses from one nerve cell to another." By blocking these channels, zonisamide prevents nerve cells from synchronizing their activity and abnormal electrical activity from spreading to other parts of the brain. This reduces the chances of a seizure occurring. Zonegran also acts on the named neurotransmitter. gamma-aminobutyric acid (GABA), a chemical that allows nerve cells to communicate with each other. This can help stabilize the electrical activity of the brain.
How has Zonegran been studied?
The applicant presented data on experimental models from the scientific literature.
Zonegran was investigated as add-on therapy in a major study involving 351 patients with partial seizures. In this study, the effects of Zonegran were compared with those of placebo (a dummy treatment). The dose of Zonegran was gradually increased over a six-week period, then kept stable over a period of 18 weeks. The main measure of effectiveness was the change in the frequency of partial seizures over the period 12 weeks prior to onset. of therapy and the treatment period of 18 weeks with the fixed dose.
What benefit has Zonegran shown during the studies?
Zonegran was more effective than placebo in reducing the frequency of attacks. Patients treated with 500 mg of Zonegran daily experienced an average reduction in seizure frequency of 51% compared with 16% of patients treated with placebo.
What is the risk associated with Zonegran?
The most commonly reported side effects with Zonegran (seen in more than 1 in 10 patients) are anorexia (severe decrease or disappearance of appetite), agitation, irritability, confusion, depression, ataxia (lack of muscle coordination), dizziness, deficit memory loss, sleepiness, diplopia (double vision) and lower levels of bicarbonate in the blood. Severe skin rashes have been observed in patients taking Zonegran, including cases of Stevens-Johnson syndrome (a type of acute allergic reaction, life-threatening life). For the full list of side effects reported with Zonegran, see the Package Leaflet.
Zonegran must not be used in people who may be hypersensitive (allergic) to zonisamide, to any of the other ingredients or to sulfonamides (such as some antibiotics).
Why has Zonegran been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that Zonegran's benefits are greater than its risks as an adjunct therapy in the treatment of adult patients with partial seizures, with or without secondary generalization, and therefore recommended that it be released. authorization to market the product.
Other information about Zonegran:
On March 10, 2005, the European Commission granted Eisai Limited a "Marketing Authorization" for Zonegran, valid throughout the European Union.
For the full version of Zonegran's EPAR, click here.
Last update of this summary: 04-2008
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