Aims: The purpose of this study was to examine the result of administrating topiramate (TPM) to patients with epilepsy that is refractory to treatment with two or more antiepileptic agents.
Patients and methods: A total of 50 patients were evaluated, 90% of which had partial seizures (simple partial, complex partial and partial with secondary generalisation) and the remaining 10% suffered from generalised seizures. The most frequent aetiology was that which corresponded to the symptoms (52% of the cases). 98% of the patients were treated with two or three drugs. TPM was added with a dosage interval between 75 and 550 mg and follow-up visits were carried out throughout a period of nine months.
Results: 12 patients remained seizure-free for at least the first three months of the study; in 20 patients the number of seizures decreased by 50% or more; in 14 patients no changes were observed, and in the other four there was an increase in the number of seizures. The best results were obtained in cases of seizures with an idiopathic aetiology, while complex partial seizures offered the worst results. We also analysed the factors that might exert an influence on the different degrees of response.
Conclusions: TPM was effective in all kinds of seizures. 24% of the patients became seizure free, and the total percentage of respondents rose to 64%. No patients dropped out of the study because of intolerance to the drugs.