Seizure worsening with topiramate amongst Indians with refractory epilepsy.

In a prospective open label add-on study on 95 patients (age 1-63 years, mean 17.76 +/- 13.83 years) with seizures refractory to conventional antiepileptic drugs (AEDs) and other new AEDs, the addition of Topiramate (TPM) resulted in seizure worsening in 18 patients (19%) necessitating drug withdrawal over an average follow-up period of 4.94 +/- 1.69 months. Patients who had seizure worsening were older (P = 0.02), were more likely to have had a history of status epilepticus in the past (P = 0.03), were on three conventional AEDs (P = 0.027) or had tried one of the other new AEDs in the past with poor response (P = 0.04). Seven of 18 patients who had seizure worsening with TPM (7.4%) experienced initial seizure worsening, probably representing the subgroup with 'true' seizure worsening whilst 11 (11.6%) had initial improvement followed by 'apparent' seizure worsening. Initial seizure worsening was noted to be significantly more in females when compared with males who worsened after initial improvement (P = 0.05).