Gabapentin add-on therapy with adaptable dosages in 610 patients with partial epilepsy: an open, observational study. The French Gabapentin Collaborative Group.
The objectives were to evaluate gabapentin add-on therapy in a large population under conditions close to real practice and to determine the therapeutic doses as reached with adaptable dosages. A 6-month multicentre, open-label study, involved addition of gabapentin to pre-existing treatment at the initial dosage of 1200 mg and subsequent adjustment between 900 and 2400 mg/day according to efficacy and tolerability. A study group of 610 adult patients, with partial epilepsy, persistent seizures and a median seizure frequency with a baseline of 7.2 per month were recruited; one-third had less than four seizures per month. Polypharmacy was frequent, with a mean of 2.3 concomitant drugs. After 6 months, 368 patients (62%) continued on gabapentin, at a mean dosage of 1739 mg/day with 44% of responders. On an intention-to-treat basis, median reduction in frequency was 21.2%, and the responder rate was 33.9%. The responder rate increased to 40.7% in the less severe subgroup receiving only one concomitant drug. Seventy-nine patients (13.4%) remained without seizures during the last evaluation period, versus nine (1.5%) during the baseline. Most of them had initially less than four seizures per month. The most frequent adverse effects, somnolence (29.3%), asthenia (14.6%), nausea (7.9%), ataxia (7.7%) and vertigo (7.2%), occurred rapidly after initial titration to 1200 mg/day, and were usually transitory. Weight gain (8.8%) seemed to be related to gabapentin dose. The combination of two recent drugs, vigabatrin and gabapentin, in 190 patients led to similar efficacy levels, with a tendency for more frequent somnolence and asthenia.
Baulac
M
M
Epilepsy Unit, Hôpital de la Pitié-Salpêtrière, Paris, France.
Cavalcanti
D
D
Semah
F
F
Arzimanoglou
A
A
Portal
J J
JJ
D000085:Acetates / Q000008:administration & dosage* / Q000009:adverse effects; D000293:Adolescent; D000328:Adult; D000368:Aged; D000588:Amines; D000927:Anticonvulsants / Q000008:administration & dosage* / Q000009:adverse effects; D003509:Cyclohexanecarboxylic Acids; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004569:Electroencephalography / Q000187:drug effects; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000188:drug therapy*; D005260:Female; D000077206:Gabapentin; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome; D020888:Vigabatrin; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives
D000085:Acetates; D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D020888:Vigabatrin