Gabapentin versus vigabatrin as first add-on for patients with partial seizures that failed to respond to monotherapy: a randomized, double-blind, dose titration study. GREAT Study Investigators Group. Gabapentin in Refractory Epilepsy Add-on Treatment.
OBJECTIVE
Our objective was to compare the efficacy and safety of gabapentin and vigabatrin as first-line add-on treatment in patients with partial epilepsy.


METHODS
This was a multicenter, double-blind, randomized dose titration study. After baseline assessment and randomization, the dose could be increased if seizures persisted and reduced if side effects occurred. Health-related quality of life was assessed at baseline and at the end of the study. By a protocol amendment post hoc, all randomized patients were offered a standardized perimetry examination at the end of the study. Improvement rate was the proportion of patients with a reduction of seizure frequency of at least 50% during an 8-week period without any adverse events causing withdrawal.


RESULTS
One hundred two patients were randomized and analyzed on an intent-to-treat basis. The improvement rate was 48% in the gabapentin group and 56% in the vigabatrin group. The improvement rate, when per protocol criteria were fulfilled, was 57% in the gabapentin group and 59% in the vigabatrin group. The proportion of seizure-free patients was 31% in the gabapentin group and 39% in the vigabatrin group. There was no difference in quality-of-life scores between the groups. Perimetry after termination of the study on 64 patients showed abnormal results in 3 of 32 patients in the vigabatrin group.


CONCLUSIONS
Approximately one third of the patients in both groups became seizure-free. Although no major differences were seen in terms of the improvement rate between the groups, equivalence between the two drugs was not found.
Lindberger
M
M
Department of Neurology, Karolinska Institute, Huddinge Hospital, Sweden. martin.lindberger@neuro.hs.sll.se
Alenius
M
M
Frisén
L
L
Johannessen
S I
SI
Larsson
S
S
Malmgren
K
K
Tomson
T
T
D000085:Acetates / Q000008:administration & dosage / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000588:Amines; D000927:Anticonvulsants / Q000008:administration & dosage / Q000627:therapeutic use*; D002648:Child; D003509:Cyclohexanecarboxylic Acids; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D004828:Epilepsies, Partial / Q000188:drug therapy*; D005260:Female; D000077206:Gabapentin; D006801:Humans; D008297:Male; D008875:Middle Aged; D012107:Research Design; D012189:Retrospective Studies; D016896:Treatment Outcome; D020888:Vigabatrin / Q000008:administration & dosage / Q000627:therapeutic use*; D005680:gamma-Aminobutyric Acid
D000085:Acetates; D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D020888:Vigabatrin