Long-term safety and efficacy of zonisamide in patients with refractory partial-onset epilepsy.
OBJECTIVE
To investigate whether zonisamide remains effective and well tolerated in the treatment of refractory partial epilepsy during long-term treatment and with flexible dosing in clinical practice.


METHODS
Patients with refractory partial epilepsy who completed a fixed-dose, randomized, double-blind clinical trial were recruited in an open-label extension study with adjustment of zonisamide and other antiepileptic drug dosage according to the treating physician's usual clinical practice.


RESULTS
An intention-to-treat analysis of 317 patients showed that zonisamide was well tolerated with a predictable safety profile. Patient retention rates at 1, 2 and 3 years were 65.3%, 44.5% and 28.8%, respectively. Zonisamide treatment was associated with a maintained reduction in seizure frequency, with some patients achieving prolonged periods of seizure freedom.


CONCLUSIONS
Flexible dosing with zonisamide demonstrated a good safety profile and sustained efficacy in the long-term adjunctive treatment of refractory partial epilepsy.
National Hospital for Neurology & Neurosurgery, Queen Square, London, UK. s.wroe@prion.ucl.ac.uk
S J
SJ
Wroe
A B
AB
Yeates
A
A
Marshall
D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D004828:Epilepsies, Partial / Q000188:drug therapy*; D006801:Humans; D007555:Isoxazoles / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use*; D008137:Longitudinal Studies; D012449:Safety; D013997:Time Factors; D016896:Treatment Outcome; D000078305:Zonisamide
D000927:Anticonvulsants; D007555:Isoxazoles; D000078305:Zonisamide