Banzel (rufinamide) is generally used as add-on (adjunctive) therapy for seizures associated with the Lennox-Gastaut syndrome that are not well controlled by other medications. These seizures may include simple partial, complex partial, secondarily generalized tonic-clonic, primarily generalized tonic-clonic, atonic, tonic, absence and myoclonic seizures. However, limited experience with Banzel is available for some of these specific seizure types.

Before being approved for marketing in most countries, regulatory authorities (the FDA in the US) review results of clinical trials that must document that the medication is effective for the purpose stated and is reasonably safe. Clinical trials of seizure medicines, including Banzel, usually are done by adding on the medicine to regimens that are not working well. Therefore, the benefit of a new drug seen in tests usually is incremental, and in people who have seizures that are proven to be difficult to control. A drug might be expected to show greater degrees of benefit in people whose seizures are not so severe, though data on this point usually are lacking.

Studies of Banzel were performed on 138 patients who had an average of at least 90 seizures per month, and were taking 1-3 other seizure medicines. Over 1-2 weeks, the Banzel dosage was increased to 45 mg/kg/day or a maximum of 3200 mg. Dose was split into two equal amounts, each given twice a day. The group given Banzel experienced a median 33% reduction in total seizures, and a 43% reduction in tonic and atonic seizures. These improvements were better than those given placebo pills.