100 Migraine Drugs, A to Z: zonisamide

Zonisamide (Zonegran) is an epilepsy drug similar to topiramate in its mechanism of action. Unfortunately, it shares its side effects as well. These include fatigue, difficulty with concentration and memory, nausea, and other. However, because they are not identical drugs, some patients tolerate zonisamide better than topiramate.

One study showed that 44% of 172 patients who did not respond to topiramate did respond to zonisamide with 13% having an excellent response. A similar study in 63 patients who did not respond to topiramate also showed benefit from zonisamide as did 34 patients in another study. Zonisamide also helped 8 out of 12 children who did not respond to other medications.

The dose of zonisamide ranges from 50 to 400 mg a day, but most patients need 100-200 mg.