What are the effects of zonisamide add-on therapy for people with uncontrolled focal epilepsy?

Abstract

Compared with placebo, for people (mostly adolescents and adults) with focal epilepsy uncontrolled by at least one antiepileptic drug, moderate‐certainty evidence shows that zonisamide led to more people achieving a reduction of at least 50% in seizure frequency (351 vs 188 per 1000 people; all results on average) but also to a higher rate of withdrawal from treatment (144 vs 100 per 1000 people). Risk of ataxia (67 vs 17 per 1000 people), somnolence (67 vs 44 per 1000 people), agitation or irritability (138 vs 59 per 1000 people), and anorexia (137 vs 50 per 1000 people) was probably higher with zonisamide, but the incidence of other adverse effects was uncertain, as results were very imprecise.