Factors Associated with Good Seizure Control in Patients on Valproic Acid

Abstract

Objective: This study aims to generate a reference range for valproic acid (VPA) in this cohort and determine the factors associated with good seizure control in patients taking this drug.Materials and Methods: We conducted a prospective, cohort, observational study among patients withepilepsy who received VPA treatment at Hospital Kuala Lumpur. The patients were considered to have goodcontrol if they had a 50% or higher seizure reduction in the one-year study period compared with the previous year. The VPA reference range was generated from those patients who had good control and whosedrug concentration values were available. Multiple logistic regression analysis with a backward likelihood ratiomethod was applied to assess the predicting factors for good seizure control.Results: A total of 242 patients were recruited and followed up for one year. The VPA reference range wasdetermined to be 40-85 mg/L. After multivariate analysis, significant predictive variables for good controlwere monotherapy [adjusted OR 4.74, 95% CI: 2.258, 9.947, p