IF A FIRST ANTIEPILEPTIC DRUG FAILS TO CONTROL A CHILDS EPILEPSY, WHAT ARE THE CHANCES OF SUCCESS WITH THE NEXT DRUG

Objective: This study was carried out to determine how often a child's epilepsy is controlled and remits if a first antiepileptic drug (AED) fails to control seizures. Study design: We used the Nova Scotia popu lation-based epilepsy study, which identified children between 1977 an d 1985 who had two or more unprovoked seizures without progressive cau se and followed them up for at least 4 years. Seizure types were parti al, primary, and secondarily generalized (excluding absence seizures). The study documented success or failure of the initial AED in the fir st year of treatment, as well as long-term seizure control and remissi on. Results: The number of eligible children was 417, with an average follow-up period of 8 years. The initial prescribed AEDs were phenobar bital (48%), carbamazepine (38%), and phenytoin (11%). Overall, 345 (8 3%) children received only one AED in the first year of treatment; 61% became free of seizures and no longer required AED treatment at the e nd of follow-up (remission). Only 4% of those treated with a single AE D during the first year later experienced intractable epilepsy. In con trast, 72 of 417 (17%) had inadequate seizure control with their first AED and received a second AED, with only 42% having complete remissio n of their epilepsy. The 72 children in whom seizures were not control led with the first AED were more likely to have neurologic deficits (p = 0.01) and complex partial seizures (p = 0.01), and 29% had intracta ble epilepsy (p < 0.0001). Conclusions: If the first AED is not effica cious, the outcome is less favorable, although many children will have remission of their epilepsy. Invasive or complex treatments for epile psy with partial and generalized tonic-clonic seizures should not be u sed until at least two AEDs have failed to control seizures.