The frequency of treatment failures due to lack of seizure control (P < 0.001) and intolerable adverse events (P < 0.037) was significantly different among the treatment groups, with the largest proportion of lack of seizure control in the lamotrigine cohort, and the largest proportion of adverse events in the valproic acid group. One large randomised, parallel double‐blind controlled trial comparing ethosuximide, lamotrigine and sodium valproate in 453 children with newly diagnosed childhood absence epilepsy found that at 12 months, the freedom‐from‐failure rates for ethosuximide and valproic acid were similar and were higher than the rate for lamotrigine. Due to the differing methodologies used in the trials comparing ethosuximide, lamotrigine and valproate, we thought it inappropriate to undertake a meta‐analysis.
There are no placebo‐controlled trials for ethosuximide or valproate, and hence, no evidence from RCTs to support a specific effect on AS for either of these two drugs. Six of them were of poor methodological quality (unclear or high risk of bias) and seven recruited less than 50 participants. Eight small trials (total number of participants: 691) were included from the earlier review. On the basis of our selection criteria, we included no new studies in the present review.
