Pharmacological outcomes in teenagers with newly diagnosed epilepsy: A 30-year cohort study

Abstract

Objective: To evaluate the long-term pharmacological outcomes in teenagers with different epilepsies. Method: This study included teenagers aged 13-19 years at treatment initiation who were newly treated with antiepileptic drugs (AEDs) at the epilepsy unit of the Western Infirmary in Glasgow, Scotland, between 1 September 1982 and 30 September 2012. Patients were prospectively followed until 30 April 2016, or death, with at least a 2-year follow-up. Results: A total of 332 adolescent patients (53% female; median age 16 years; 54% with generalized epilepsy) were included. At the end of the study, 221 patients (67%) were seizure-free. A higher seizure-free rate was observed in those with generalized compared to focal epilepsy (72% versus 60%, P = 0.01). During the study, 108 patients had relapses after periods of being seizure-free, most commonly due to poor adherence to AEDs (49%, n = 53/108). AED withdrawal was associated with a high risk of seizure recurrence (70%, n = 26/37), but 56% (n = 61/108) of relapsed patients became seizure-free again by the end of the study, with only 9% (n = 31/332) meeting the International League Against Epilepsy (ILAE) definition of pharmacoresistance during follow-up. Of the 221 seizure-free patients, 83% achieved this on monotherapy. There was no significant difference in efficacy rate between new and standard AED monotherapy (74% versus 77%, P = 0.66). The overall poor tolerability rate of AEDs was 21% (n = 69/332). Among the different new and standard AEDs used as initial monotherapy, lamotrigine was associated with the lowest rate of adverse effects (12%, n = 15/124), while topiramate was associated with the highest rate (56%, n = 5/9). Significance: Teenagers with epilepsy showed good seizure control, particularly those with generalized epilepsy. However, relapse was common and there was high risk of seizure recurrence after treatment withdrawal. Most patients were controlled on monotherapy. As the efficacy of AEDs was comparable, tolerability can be a primary consideration for AED selection in this population.