Abstract

SummaryBackground The relative risks and benefits of starting or withholding antiepileptic drug treatment in patients with few or infrequent seizures are unclear. We sought to compare policies of immediate versus deferred treatment in such patients and to assess the effects of these policies on short-term recurrence and long-term outcomes. Methods We undertook an unmasked, multicentre, randomised study of immediate and deferred antiepileptic drug treatment in 1847 patients with single seizures and early epilepsy. Outcomes comprised time to first, second, and fifth seizures; time to 2-year remission; no seizures between years 1 and 3 and between years 3 and 5 after randomisation; and quality of life. Analysis was by intention to treat. Findings 404 patients invited to join the trial did not consent to randomisation; 722 were subsequently assigned immediate treatment with antiepileptic drugs and 721 were assigned deferred treatment. Immediate treatment increased time to first seizure (hazard ratio 1·4 [95% CI 1·2 to 1·7]), second seizure (1·3 [1·1 to 1·6]), and first tonic-clonic seizure (1·5 [1·2 to 1·8]). It also reduced the time to achieve 2-year remission of seizures (p=0·023). At 5-years follow-up, 76% of patients in the immediate treatment group and 77% of those in the deferred treatment group were seizure free between 3 and 5 years after randomisation (difference −0·2% [95% CI −5·8% to 5·5%]). The two policies did not differ with respect to quality of life outcomes or serious complications. Interpretation Immediate antiepileptic drug treatment reduces the occurrence of seizures in the next 1–2 years, but does not affect long-term remission in individuals with single or infrequent seizures.