Adverse Effects of Antisizure Medications Among Adults with Epilepsy at Teaching Hospital, Jaffna

Abstract

Background: Antiseizure medications (ASMs) are the cornerstone of epilepsy management. However, adverse effects (AEs) associated with ASMs may affect adherence and, thereby, the control of epilepsy. This study aimed to evaluate the treatment pattern and adverse effects of ASMs among adults with epilepsy who are being followed up at Teaching Hospital, Jaffna. Methods: A descriptive cross-sectional study was conducted among adult patients receiving ASMs for ≥3 months at the neurology outpatient clinic, Teaching Hospital, Jaffna. Eligible participants were recruited using consecutive sampling over a 4-month period. Data were collected using a pretested interviewer-administered questionnaire developed by the investigators based on the literature. The questionnaire captured sociodemographic and clinical characteristics, ASM use, and self-reported adverse effects. Logistic regression was performed to determine the factors associated with adverse effects. A p ≤ 0.05 is considered statistically significant. Results: Data from 213 participants were analysed. The mean age was 36.3 ± 0.92 years, and the majority (52%) were males. Focal seizure (n=129, 60.6%) was the most common type. Nearly two-thirds (64.8%) received dual or polytherapy, and older (first-generation) ASMs were predominantly prescribed (74.5%). Only one-third (34%) were seizure-free for ≥ 2 years. A total of 333 AEs were reported in 146 participants (prevalence 68.5%; mean 1.6 per patient). Common AEs included sedation (27%), memory impairment (24%), and dizziness (21%). Advancing age (AOR 4.3; 95% CI: 1.87–10.29; p<0.001), late onset of epilepsy (AOR 0.35; 95% CI: 0.14–0.87; p=0.023), and polytherapy (AOR 2.7; 95% CI: 1.4–5.3; p=0.003) were significantly associated with AEs. Valproic acid and clobazam were significantly associated with sedation (p<0.001 and p=0.003, respectively) and dizziness (p=0.013 and p=0.006, respectively), while carbamazepine was significantly associated with memory impairment (p=0.022). Among those who experienced AEs, one-fourth required switching ASMs. Carbamazepine was the most commonly replaced ASM, and levetiracetam was the most common alternative. Conclusion: Older antiseizure medications and polytherapy were commonly prescribed, and adverse events were frequent. Larger studies are needed to evaluate current prescribing practices and develop strategies to optimise epilepsy care.