“…These characteristics could be credited to a state‐dependent Na + channel blocking mechanism (Rogawski & Porter, 1990) and were shared by anticonvulsant drugs such as phenytoin, carbamazepine and lamotrigine (Willow et al , 1985; Leach et al , 1986; Backus et al , 1991). However, unlike topiramate, these drugs act by more than one mechanism and inhibit synaptic responses at a low stimulation frequency (1 pulse per 20 s), an effect which is likely due to inhibition on the Ca 2+ channels (Wang et al , 1996; Stefani et al , 1996; Cheng et al , 1997). In this respect, topiramate is expected to provide a more selective therapy with fewer adverse effects, although the question of whether an absolute selectivity of a drug is desirable in seizure therapy that involves complex adaptive changes is still in doubt (Loscher, 1998).…”