Zonisamide in clinical practice

Zonisamide is currently licensed in Europe and the USA for the adjunctive treatment of partial seizures (with or without secondary generalization) in adults, based on the results of four pivotal, randomized, double-blind, placebo-controlled trials. It is also licensed in Europe as monotherapy for adults with newly diagnosed partial epilepsy, based on the results of a randomized, double-blind, non-inferiority trial. Because clinical trials are conducted under tightly controlled conditions, using rigid dosing schedules and employing strict exclusion/exclusion criteria, there is a need for 'real-world' evidence of an antiepileptic drug's effectiveness and tolerability in clinical practice, where patients are much more diverse in terms of clinical characteristics and treatment is tailored to the individual's specific needs. Several studies have demonstrated that adjunctive treatment with zonisamide is effective when administered under everyday clinical practice conditions, with a favourable safety/tolerability profile similar to that observed in clinical trials. In the Zonisamid im Alltag Der Epilepsiepatienten (ZADE) study, almost 80% of patients showed a reduction in seizure frequency of ≥50% over a median follow-up of 18 weeks, and over one-third of patients became seizure free. Data from these clinical practice studies also indicate that zonisamide is effective and generally well tolerated when administered as a first-line adjunctive treatment and is associated with high retention rates and improvements in quality of life. Evidence from these clinical practice studies therefore complements data from zonisamide's clinical trial programme, providing pragmatic information on the likely benefits and risks of treatment under real-life conditions.