title: Retention, dosing, tolerability and patient reported seizure outcome of Zonisamide as only add-on treatment under real-life conditions in adult patients with partial onset seizures: Results of the observational study ZOOM.
abstract: OBJECTIVE
  Zonisamide is licensed for adjunctive therapy for partial-onset seizures with or without secondary generalisation in patients 6 years and older and as monotherapy for the treatment of partial seizures in adult patients with newly diagnosed epilepsy, and shows a favourable pharmacokinetic profile with low interaction potential with other drugs. The aim of the present study was to gather real-life data on retention and modalities of zonisamide use when administered as only add-on treatment to a current AED monotherapy in adult patients with partial-onset seizures.
  
  
  METHODS
  This multicenter observational study was performed in 4 European countries and comprised three visits: baseline, and after 3 and 6 months. Data on patients' retention, reported efficacy, tolerability and safety, and quality of life was collected. Of 100 included patients, 93 could be evaluated.
  
  
  RESULTS
  After 6 months, the retention rate of zonisamide add-on therapy was 82.8%. At this time, a reduction of seizure frequency of at least 50% was observed in 79.7% of patients, with 43.6% reporting seizure freedom over the last 3 months of the study period. Adverse events were reported by 19.4% of patients, with fatigue, agitation, dizziness, and headache being most frequent. Approximately 25% of patients were older than 60 years, many of whom suffered from late-onset epilepsy. Compared to younger patients, these patients showed considerable differences with regard to their antiepileptic drug regimen at baseline, and slightly higher responder and retention rates at 6 months.
  
  
  CONCLUSIONS
  Despite limitations due to the non-interventional open-label design and the low sample size, the results show that zonisamide as only add-on therapy is well retained, indicating effectiveness in the majority of patients under real-life conditions.
authors.affiliation: Epilepsy Center University Hospital Erlangen, Erlangen, Germany. Electronic address: hajo.hamer@uk-erlangen.de.
authors.forename: Hajo
authors.initials: H
authors.lastname: Hamer
authors.affiliation: University PARIS VI, Paris, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Baulac
authors.affiliation: Eisai Europe Ltd, Hatfield, Hertfordshire, UK.
authors.forename: Rob
authors.initials: R
authors.lastname: McMurray
authors.affiliation: Eisai GmbH, Frankfurt, Germany.
authors.forename: Edgar
authors.initials: E
authors.lastname: Kockelmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000927:Anticonvulsants / Q000627:therapeutic use*; D004359:Drug Therapy, Combination / Q000379:methods; D004361:Drug Tolerance; D004827:Epilepsy / Q000188:drug therapy*; D005260:Female; D006801:Humans; D007555:Isoxazoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D012640:Seizures / Q000188:drug therapy*; D016896:Treatment Outcome; D055815:Young Adult; D000078305:Zonisamide
chemical_list: D000927:Anticonvulsants; D007555:Isoxazoles; D000078305:Zonisamide
keywords: Elderly; Epilepsy; Observational study; Partial-onset seizures; Retention; Zonisamide