Retigabine reduces frequency of partial-onset seizures
Adjunctive therapy with the novel antiepileptic drug retigabine (see Panel) reduces the frequency of partial-onset seizures for patients, according to a recently published study (Neurology 2007;68:1197).
Patients taking retigabine daily in three divided doses saw dose-dependent
improvements in monthly seizure frequency (600mg/day, percentage change
from baseline –23 per cent; 900mg/day, –29 per cent; 1,200mg/day, –35
per cent; placebo, –13 per cent; P<0.001 for overall difference
across all treatment arms).
The study had a 32 per cent dropout rate, with confusion, speech disorder,
dizziness and somnolence the most common side effects that led to discontinuation.
Of the patients who left the trial, 91 per cent did so during the “forced
titration” phase of the trial which, the authors say, was necessary
to separate the treatment arms but disadvantaged patients who might have
tolerated a more flexible approach.
How retigabine works
Retigabine, a carbamic acid derivative, shows broad-spectrum anticonvulsant
action through the following mechanisms:
• Enhancing potassium current mediated by human KCNQ2 and KCNQ3
potassium channels
• Potentiating gamma aminobutyric acid (GABA)-evoked currents in
cortical neurons
• Blocking 4-aminopyridine-induced neosynthesis of neuroactive
amino acids
• Stimulating de novo synthesis of GABA in hippocampal slices |
|
The
Pharmaceutical Journal
Acrobat
Reader