New drugs no more effective than the old ones
Although each drug must be considered on its own merits, the overall evidence indicates that using the new drugs as monotherapy has not increased the proportion of seizure-free patients (2). In 2013, the International League Against Epilepsy reviewed 11 meta-analyses and 64 randomised clinical trials comparing the efficacy of the old versus new drugs. The conclusion was clear: the new drugs have not reduced the proportion of pharmacoresistant patients (3). Similar studies conducted after 2013 have not shaken that conclusion (4, 5).
A Scottish study showed that in 2000, around 64 % of 470 patients with new-onset epilepsy achieved seizure freedom for at least one year, mainly with the older drugs (6). But that percentage was no higher among 1 795 patients in 2014, after the new drugs had been introduced (7).
In our experience, several of the new drugs have little effect on seizure frequency, but they reduce seizure severity
In most studies, the new drugs have been compared with carbamazepine in the form of extended-release tablets. Levetiracetam, zonisamide, lacosamide and eslicarbazepine have been found to be as efficacious as phenytoin and carbamazepine (level 1 evidence) in adults with focal epilepsy. In elderly patients with new-onset focal epilepsy, lamotrigine and levetiracetam were as efficacious as carbamazepine (8).
Meta-analyses of randomised clinical trials in children and adolescents with new-onset focal seizures have shown no difference in efficacy between phenobarbital, phenytoin, carbamazepine and valproate, or between lamotrigine and oxcarbazepine. A slight trend was seen in favour of carbamazepine and lamotrigine (9). In childhood absence epilepsy, ethosuximide and valproate were shown to be superior to lamotrigine (10).