[Clinical application of newer anti-epileptic drugs]

Newer anti-epileptic drugs (nAEDs) have been introduced in Japan, including zonisamide (ZNS), gabapentine (GBP), topiramate (TPM), lamotrigine (LTG), and levetiracetam (LEV). Because nAEDs have different properties from older AEDs, they may provide a better control of the seizures and a more favorable safety and tolerability profile. Indeed, the systematic meta-analyses of randomized control trials demonstrated that the odds ratios for 50% responder rate were ZNS 2.7-2.99, GBP 2.02-2.29, TPM 4.07-5.22, LTG 2.32-2.87, and LEV 3.75-5.33, indicating their clinical efficacy. These studies also showed that the odds ratios for discontinuation were ZNS 1.78-4.23, GBP 0.99-1.36, TPM 2.38-2.56, LTG 1.16-1.19, and LEV 0.97-1.26, indicating their good tolerability. In the guidelines and the expert opinions, it was demonstrated that nAEDs can be used as the second-line drugs for both partial and generalized seizures. Furthermore, because nAEDs may have fewer drug-interactions, fewer adverse effects, and different mechanisms, it was also demonstrated that nAEDs are rather ideal as an add-on drug. It was also reported that nAEDs are less harmful for females of reproductive age.