Impact of Drug Manipulation on Seizure Freedom in Adults with Uncontrolled Epilepsy: A Prospective Controlled Study in Rural China.

Abstract

It has been suggested that uncontrolled epilepsy might not necessarily equate to drug resistance when antiepileptic drugs (AEDs) are used at relatively low doses, a practice frequently observed in rural areas of China. To assess the clinical benefits of further drug manipulation in this situation, we prospectively followed up the outcomes of patients with uncontrolled epilepsy while taking relatively low doses of AEDs. The study included patients aged 16years and older with uncontrolled epilepsy and who were receiving at least one AED at a dosage below 50% of the World Health Organization (WHO) defined daily dose (DDD) (50% DDD) (Group1). Patients with drug-resistant epilepsy were included for comparison (Group2). Both groups were followed-up for at least 2years. Seizure outcomes after further drug manipulations were recorded at the last follow-up. A total of 197 patients (55.3% male) were included in Group1 and 32 (46.9% male) in Group2; their mean duration of follow-up was 28.85±1.90 and 30.91±2.04months, respectively. At the last follow-up, 16.8% (33/197) of patients in Group1 had become seizure-free compared with none in Group2 (p<0.001). Seventeen of 93 (18.3%) patients in Group1 became seizure free after increasing the dosage of baseline AED(s) alone. Only 5.5% (3/55) of patients who had failed to respond to an AED at ≥50% DDD at baseline became seizure free compared with 21.1% (30/142) who did not have such a history (p=0.001). The number of AEDs taken at a dosage below 50% DDD at baseline was not associated with seizure outcome. Uncontrolled epilepsy could become controlled in a substantial proportion of patients by dose increase alone, particularly if there is no history of drug failure at ≥50% DDD.