Treatment Outcome after Failure of a First Anti-epileptic Drug

In the August 2014 issue of Neurology, Dr. Bonnett and colleagues, investigators from the Standard and New Antiepileptic Drugs (SANAD) trial, present results regarding treatment outcome after failure of a first anti-epileptic drug. The SANAD trial evaluated the use of carbamazepine, gabapentin, lamotrigine, topiramate, or oxcarbazepine in 1,721 people with focal epilepsy and 716 people with generalized epilepsy randomized to either lamotrigine, topiramate, or valproate.  Their outcomes were time to 12 months remission and time to second treatment failure.

The investigators found:

• 44% of people in the SANAD trial had a first treatment failure. 
• 75% of these subsequently achieved 12 months remission by six years of follow-up.
• Prognostic factors that seem to impact this outcome included gender, age at treatment failure, time on randomized treatment at treatment failure, neurologic insult, total number of tonic clonic seizures at treatment failure, reason for treatment failure, seizure type and CT/MRI scan result. 
• Young people without tonic clonic seizures with a normal CT/MRI scan and failing their treatment because of unacceptable adverse events had the highest likelihood of 12 month remission. 
• 50% of people who failed the first treatment also failed their second. 
• Significant prognostic factors for this outcome included total number of tonic clonic seizures at first treatment failure, reason for first treatment failure, and CT/MRI scan results. 
• People with tonic clonic seizures and failing because of inadequate seizure control had the highest risk of a second treatment failure. 
• The authors concluded that a high proportion of individuals will achieve 12 month remission after a first treatment failure. Clinical factors can help to predict outcome.