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Retention rate of zonisamide in intractable epilepsy
Author(s) -
Nakken K. O.,
Lindstrøm P.,
Andersen H.
Publication year - 2015
Publication title -
acta neurologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.967
H-Index - 95
eISSN - 1600-0404
pISSN - 0001-6314
DOI - 10.1111/ane.12379
Subject(s) - zonisamide , intractable epilepsy , epilepsy , medicine , psychiatry , topiramate
Objectives To assess the effect and tolerability of zonisamide ( ZNS ) as adjunctive treatment for difficult‐to‐treat epilepsy in adult Scandinavian patients. Material and methods 151 outpatients (mean age: 42.5 years) from 18 centres in Denmark, Sweden and Norway were recruited to the study. 81.5% had focal epilepsy, and the mean number of previously tried AED s was 4.5. The patients were given ZNS as add‐on treatment, and the ZNS dosing and the visit frequency were governed by the treating physician. The primary efficacy endpoint was the retention rate after 12‐month treatment. Assessments included also responder rate, type and frequency of adverse events, healthcare resource utilization ( HCRU ) and quality of life ( QOLIE ‐31). Results 90 patients (59.6%) completed the study. Mean daily ZNS dose was 300.8 mg. After 12 months, 81 patients were still on ZNS , that is a retention rate of 53.6%. The mean reduction of seizure frequency at 12 months was 27%. Best effect was seen in those with focal and those with secondary generalized seizures. In the QOLIE ‐31, there was a mean increase from baseline of 4.8 points. The tolerability was generally good. The majority of side effects were CNS ‐related, dizziness, fatigue, seizure aggravation, and headache being most prevalent. 21.2% had adverse events leading to withdrawal of ZNS . Conclusions A retention rate of 53.6% after 1 year of treatment with ZNS is roughly in accordance with the retention rates found for lamotrigine, oxcarbazepine, levetiracetam and topiramate in drug‐resistant patients.