Pharmacist impact on adherence of valproic acid therapy in pediatric patients with epilepsy using active education techniques

Abstract

There is limited information on the impact of active education by a pharmacist in the population of pediatric patients with epilepsy (PWE) in China. The objective of this study was to assess the effect of education by pharmacists on medication adherence and percentage of valproic acid (VPA) samples reaching therapeutic reference range in these patients. This study was conducted at two teaching hospitals in Changsha, China. Patients were retrospectively identified from January 2016 to December 2017. Active education by a pharmacist in both oral and written formats was provided at the intervention hospital whereas standard passive pharmacist service (dispensing and answering questions) was provided at the control hospital. Medication adherence was assessed by the simplified medication adherence questionnaire (SMAQ), and serum concentrations of VPA were collected. The correlation between pharmacist education and medication adherence and percentage of VPA samples reaching therapeutic reference range were analyzed. A total of 2165 patients and 4343 serum VPA concentrations were included in the analysis. For the first therapeutic drug monitoring (TDM) measurement, there was no statistical difference between the two hospitals: 41.3% of VPA samples reached therapeutic range at the intervention hospital compared with 45.4% at the control hospital (χ2 = 3.686, P > 0.05). After pharmacist intervention at the intervention hospital, however, there were significant differences in the percentage of therapeutic VPA samples reaching therapeutic range between the first and the second, third, fourth, and fifth TDM measurements (χ2 = 9.756, P < 0.01; χ2 = 22.840, P < 0.01; χ2 = 15.816, P < 0.01; χ2 = 27.613, P < 0.01).Based on the SMAQ adherence assessment, adherence increased from a minimum of 56.0% to a maximum of 73.9% with stabilization during the last six months of follow-up at the intervention hospital. Both the medication adherence rate and the percentage of VPA samples reaching therapeutic range increased as the result of active education by a pharmacist, suggesting that continuous pharmacist intervention had a positive impact in outpatient pediatric PWE.