Topiramate: New preparation. Helpful in refractory partial epilepsy.

(1) Topiramate is indicated in the treatment of refractory partial epilepsy, in combination with other antiepileptics. (2) Six placebo-controlled trials with sound methodology show that, in combination with an inadequately effective antiepileptic treatment, topiramate yields at least a 50% reduction in the frequency of attacks in 40-50% of patients. It seems effective in all forms of partial epilepsy. (3) There has been no direct comparison with other recent antiepileptics. (4) The adverse effects of topiramate are mainly neuropsychological. Some cases of weight loss at the outset of treatment, and kidney stones, have been described. No major adverse reactions to topiramate have been reported. (5) Topiramate seems to carry little risk of interactions with drugs with which it is likely to be combined. Enzyme inducers can reduce its efficacy. Combined oral contraception may fail in women on topiramate. (6) There is no evidence that the topiramate dose regimen can be based on plasma assays.