Treatment pattern and adverse effects of antiseizure medications among adult patients with epilepsy: A single centre observational cross-sectional study in Northern Sri Lanka

Background: Antiseizure medications (ASMs) are essential for seizure control, but they are also associated with a range of adverse effects that may affect treatment outcomes. Objective: This study aimed to evaluate the treatment pattern and adverse effects of ASMs among adult patients with epilepsy who were followed up at a tertiary-care hospital in Northern Sri Lanka. Methods: A descriptive cross-sectional study was conducted among adult patients on ASMs for ≥3 months who were receiving follow-up at Teaching Hospital Jaffna. Data were collected over four months using a pretested interviewer-administered questionnaire. Chi-square test and logistic regression were performed to determine the significance between groups and the association of independent variables, respectively. A p-value of ≤0.05 was considered statistically significant. Results: Data from 213 participants was analysed. The mean age was 36.27 ± 0.92 years, and the male-to-female ratio was almost 1. Nearly two-thirds of participants (64.8%) were on dual or polytherapy. Older ASMs were predominantly prescribed (74.5%). A total of 333 adverse effects were reported, giving a point prevalence of 68.5% and a rate of 1.6 adverse effects per person. Sedation (27%), memory impairment (24%), and dizziness (21%) were the most common adverse effects. Advancing age (adjusted OR (AOR): 4.3, 95% CI 1.87 to 10.29, p<0.001), early onset of epilepsy (AOR: 0.35, 95% CI 0.14 to 0.87, p=0.023), and the use of multiple ASMs (AOR: 2.7, 95% CI 1.4 to 5.3, p=0.003) were associated with the occurrence of adverse effects. Carbamazepine, clobazam and valproic acid were significantly (p<0.05) associated with one or more common adverse effects. Conclusion: Most patients in this study received older antiseizure medications and polytherapy. A high burden of medication-related adverse effects was also observed. Regular review and reconciliation of treatment and improving access to better-tolerated medication would reduce the medication-related burden among patients with epilepsy.