A randomized open-label observational study to compare the efficacy and tolerability between topiramate and valproate in juvenile myoclonic epilepsy

Juvenile myoclonic epilepsy (JME) is managed with valproate in most patients; however, valproate is an antiepileptic drug that has relatively severe adverse effects, especially in women. We performed a prospective, open-label, randomized observational study for comparison of efficacy and tolerability between topiramate and valproate in patients with JME. The inclusion criteria were patients with newly diagnosed JME or previously diagnosed JME with a history of a poor response or adverse effects to other antiepileptic drugs. The primary endpoint of this study was percentage of patients who were free of myoclonic seizures for 24 weeks in the two groups. The frequency and severity of adverse effects were also assessed. Sixteen patients were randomized to topiramate and 17 to valproate. In the topiramate arm, 11 of 16 patients (68.9%) completed 24-week maintenance therapy and seven of the 11 (64%) were seizure-free. In the valproate arm, 16 of 17 patients (94.1%) completed 24-week follow-up and nine of 16 (56%) were seizure-free. The difference (64% topiramate versus 56% valproate) did not reach statistical significance in this study group (p = 0.08, Fisher’s exact test). However, the severity of adverse effects was significantly different. Only 1 of 10 adverse effects from topiramate was ranked moderate-to-severe (10%), in comparison with severe rankings for 10 of 17 adverse effects from valproate (59%) (p = 0.018, Fisher’s exact test). In summary, the efficacy of topiramate and valproate was not different, but the severity of adverse effects was favourable for topiramate. Our findings suggest that valproate may be replaced with topiramate, especially for the patients with JME who do not tolerate valproate.