Sudden Cardiac Death or Ventricular Arrythmia in Patients Taking Levetiracetam or Oxcarbazepine

BACKGROUND AND OBJECTIVES: Levetiracetam is a widely used antiseizure medication. Recent concerns have been raised regarding the potential prolongation of the QT interval by levetiracetam and increased risk of sudden cardiac death. This could have profound implications for patient safety and for prescribing practice. This study assessed the potential association of levetiracetam with cardiac outcomes related to QT interval prolongation. We compared outcomes of patients taking levetiracetam with those taking oxcarbazepine as a comparator medication that has not been associated with prolongation of the QT interval. METHODS: The sample included patients who were newly prescribed levetiracetam or oxcarbazepine from January 31, 2010, to December 31, 2019, using administrative claims data from the OptumLabs Data Warehouse (OLDW). The analysis focused on a combined endpoint of sudden cardiac death or ventricular arrythmia, which are both linked to QT interval prolongation. We used a new user design and selected oxcarbazepine as an active comparator with levetiracetam to minimize bias. We used propensity score weighting to balance the levetiracetam and oxcarbazepine cohorts and then performed weighted Cox regressions to evaluate the association of levetiracetam with the combined endpoint. RESULTS: We identified 104,655 enrollees taking levetiracetam and 39,596 enrollees taking oxcarbazepine. At baseline, enrollees taking levetiracetam were older, more likely to have diagnosed epilepsy, and more likely to have diagnosed comorbidities including hypertension, cerebrovascular disease, and coronary artery disease. In the main analysis, we found no significant difference between levetiracetam and oxcarbazepine in the rate of the combined endpoint for the Cox proportional hazards model (hazard ratio [HR] 0.79, 95% CI 0.42-1.47) or Cox regression with time-varying characteristics (HR 0.78, 95% CI 0.41-1.50). DISCUSSION: When compared with oxcarbazepine, levetiracetam does not correlate with increased risk of ventricular arrythmia and sudden cardiac death. Our finding does not support the concern for cardiac risk to indicate restriction of levetiracetam use nor the requirement of cardiac monitoring when using it. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that sudden cardiac death and ventricular arrythmia are not more frequent in patients older than 17 years newly prescribed levetiracetam, compared with those prescribed oxcarbazepine.