title: Adjunctive retigabine in refractory focal epilepsy: Postmarketing experience at four tertiary epilepsy care centers in Germany.
abstract: OBJECTIVE
  Retigabine (RTG, ezogabine) is the first potassium channel-opening anticonvulsant drug approved for adjunctive treatment of focal epilepsies. We report on the postmarketing clinical efficacy, adverse events, and retention rates of RTG in adult patients with refractory focal epilepsy.
  
  
  METHODS
  Clinical features before and during RTG treatment were retrospectively collected from patients treated at four German epilepsy centers in 2011 and 2012.
  
  
  RESULTS
  A total of 195 patients were included. Daily RTG doses ranged from 100 to 1500 mg. Retigabine reduced seizure frequency or severity for 24.6% and led to seizure-freedom in 2.1% of the patients but had no apparent effect in 43.1% of the patients. Seizure aggravation occurred in 14.9%. The one-, two-, and three-year retention rates amounted to 32.6%, 7.2%, and 5.7%, respectively. Adverse events were reported by 76% of the patients and were mostly CNS-related. Blue discolorations were noted in three long-term responders. Three possible SUDEP cases occurred during the observation period, equalling an incidence rate of about 20 per 1000 patient years.
  
  
  CONCLUSIONS
  Our results are similar to other pivotal trials with respect to the long-term, open-label extensions and recent postmarketing studies. Despite the limitations of the retrospective design, our observational study suggests that RTG leads to good seizure control in a small number of patients with treatment-refractory seizures. However, because of the rather high percentage of patients who experienced significant adverse events, we consider RTG as a drug of reserve.
authors.affiliation: Department of Epileptology, University Hospital Bonn, Bonn, Germany. Electronic address: daniel.nass@ukb.uni-bonn.de.
authors.forename: R D
authors.initials: RD
authors.lastname: Nass
authors.affiliation: Epilepsiezentrum Kork, Kehl, Kork, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Kurth
authors.affiliation: Epilepsy Center Hessen and Department of Neurology, Philipps-University, Marburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Kull
authors.affiliation: Department of Neurology, University of Erlangen-Nuremberg, Germany.
authors.forename: W
authors.initials: W
authors.lastname: Graf
authors.affiliation: Department of Neurology, University of Erlangen-Nuremberg, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Kasper
authors.affiliation: Department of Neurology, University of Erlangen-Nuremberg, Germany.
authors.forename: H M
authors.initials: HM
authors.lastname: Hamer
authors.affiliation: Epilepsy Center Hessen and Department of Neurology, Philipps-University, Marburg, Germany; Epilepsy Center Frankfurt Rhine-Main, Goethe-University, Frankfurt am Main, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Strzelczyk
authors.affiliation: Department of Epileptology, University Hospital Bonn, Bonn, Germany.
authors.forename: C E
authors.initials: CE
authors.lastname: Elger
authors.affiliation: Epilepsiezentrum Kork, Kehl, Kork, Germany.
authors.forename: B J
authors.initials: BJ
authors.lastname: Steinhoff
authors.affiliation: Department of Epileptology, University Hospital Bonn, Bonn, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Surges
authors.affiliation: Epilepsy Center Hessen and Department of Neurology, Philipps-University, Marburg, Germany; Epilepsy Center Frankfurt Rhine-Main, Goethe-University, Frankfurt am Main, Germany.
authors.forename: F
authors.initials: F
authors.lastname: Rosenow
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000009:adverse effects / Q000627:therapeutic use*; D002219:Carbamates / Q000009:adverse effects / Q000627:therapeutic use*; D002648:Child; D016757:Death, Sudden, Cardiac / Q000453:epidemiology; D000069279:Drug Resistant Epilepsy / Q000188:drug therapy*; D004562:Electrocardiography / Q000187:drug effects; D004828:Epilepsies, Partial / Q000188:drug therapy*; D005260:Female; D005858:Germany; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010655:Phenylenediamines / Q000009:adverse effects / Q000627:therapeutic use*; D011358:Product Surveillance, Postmarketing; D012189:Retrospective Studies; D012640:Seizures / Q000188:drug therapy; D062606:Tertiary Care Centers; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000927:Anticonvulsants; D002219:Carbamates; D010655:Phenylenediamines; C101866:ezogabine
keywords: Ezogabine; Retigabin; Retigabine; Trobalt