To evaluate rate of seizure freedom in people with newly treated focal epilepsy after addition or switch to a sodium channel modulator after failing initial mono-therapy with levetiracetam due to efficacy and vice versa.

Since approval of levetiracetam as mono-therapy, prescription has considerably increased because of its efficacy and tolerability. Human Epilepsy Project (HEP) 1 is an observational, prospective, multi-center study that enrolled patients with newly treated focal epilepsy. The data collected included seizure frequency and anti-seizure medication (ASM) information.

Seizure frequency was collected pre and post treatment. Seizure counts were obtained from patient diaries and medical records. Failure of a medication was defined as having greater than or equal to one seizure on an adequate dose of a given medication. Participants were considered seizure free if they had no seizures for at least 6 months at time of last follow up.  Participants were grouped into two cohorts; 1) those that became seizure free after addition/switch to a sodium channel modulator after failing levetiracetam as initial mono-therapy and 2) those that became seizure free after addition/switch to levetiracetam after failing a sodium channel modulator as initial mono-therapy.

Of the 448 participants with ASM data, 70.5% (n=316) of participants were seizure free for 6 months at last follow up. 13% (41/316) of those that were 6 months seizure free were in group 1, whereas only 3.8% (12/316) were in group 2.

A greater percentage of patients achieved seizure freedom after failing levetiracetam due to efficacy with the addition or transition to a sodium channel modulator over the converse.  While levetiracetam is commonly prescribed as initial therapy, failure at adequate doses of any first mono-therapy should lead to early consideration of alternative treatments.