Gabapentin is a new
antiepileptic drug (AED) with an attractive pharmacokinetic profile. It is absorbed by an active and saturable transport system, and has a high volume of distribution.
Gabapentin is not bound to
plasma proteins, does not induce hepatic
enzymes and is not metabolized. At steady state, it has a half-life of 6-8 h, and is eliminated unchanged by renal route with a plasma clearance proportional to the
creatinine clearance. It is devoid of significant
drug-drug interactions when administered with the established AEDs or with
oral contraceptives.
Gabapentin used as an add-on AED significantly reduced the frequency of
partial seizures and secondarily
generalized tonic-clonic seizures in three large double-blind, placebo-controlled, parallel-group clinical trails. It is well tolerated, with transient
somnolence and
dizziness being the most frequent adverse effects. Although the mechanism of action of
gabapentin is not fully established, there is strong evidence to suggest a novel mechanism of action.
Gabapentin is a unique and promising
drug that could improve the quality of life of patients with
epilepsy and is a welcome addition to the armamentarium of currently available AEDs for the treatment of patients with
seizures of partial onset.