[Rational combinations of antiepileptic drugs for refractory epilepsy].

Although epilepsy surgery is most effective for patients with intractable epilepsy, a majority of them is not eligible for the surgery. Most of patients with refractory epilepsy are eventually treated with polypharmacy in hope of seizure control. Therefore, rational combinations of antiepileptic drugs are needed to control intractable seizures. Drug combinations should be rationally chosen based on the evidence of synergic efficacy and on avoidance of neurotoxicity. Several clinical studies suggest that the combination of valproate with lamotrigine has synergic antiepileptic effect. It has also been reported that the combination of carbamazepine with lamotrigine paradoxically decreases efficacy and increases toxicity. Animal studies using isobolography suggest that the combinations of topiramate with lamotrigine or levetiracetam are also promising on both seizure control and neurotoxicity. Clinical research is needed to examine these combinations.