Lamotrigine Use Is Associated with Ventricular Tachycardia: An Observational Cohort Study
Abstract number :
2.392
Submission category :
7. Anti-seizure Medications / 7D. Drug Side Effects
Year :
2024
Submission ID :
1206
Source :
www.aesnet.org
Presentation date :
12/8/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Przemysław Radwański, PharmD, PhD – The Ohio State University
Sodam Kim, PharmD – University of Illinois at Chicago
Landon Welch, BS – University of Utah
Bertha De Los Santos, PharmD – University of Illinois at Chicago
Kibum Kim, PhD – University of Illinois at Chicago
Mark Munger, PharmD – University of Utah
Rationale: Lamotrigine is a voltage-gated sodium channel blocker frequently employed in management of epilepsy and bipolar disorder. Based on in vitro data, FDA has recently issued a safety warning on the cardiac effects of lamotrigine; however, the translatability of the in vitro findings to a clinical setting is unknown. Here we set out to examine the association between lamotrigine use and the onset of ventricular tachycardia (VT).
Methods: Rates of VT incidents, identified by the appearance of newly recorded ICD codes, were compared using Merative MarketScan® Commercial Claims and Medicare Supplemental Database. Patients who filled a prescription for lamotrigine or control, which included lithium, quetiapine, valproate, or risperidone were enrolled in the study. We excluded patients with arrhythmia (ventricular or atrial) during the 6-month baseline period before study enrolment. We calculated cumulative incidence of VT using Kaplan-Meier estimator at end of one-year follow up. Multivariable regression model was used to calculate hazard ratio for VT incidence, which was adjusting for baseline characteristics, including structural heart disease. Patients were censored at the last enrollment date of the continuous enrollment period, at the time their therapy was switched, or discontinuation of therapy.
Results: The study cohort consisted of 153,852 lamotrigine and 213,593 control patients. The 1-year cumulative incidence of VT for lamotrigine vs. control patients was 0.785% vs. 0.683%, calculating HR of 1.270 [95% CI: 1.079-1.496], p=0.0041. When adjusted for baseline characteristics, the 24-month HR was 1.326 [1.122-1.568], p-value = 0.0009. The impact of lamotrigine on VT incidence was particular evident in patients ≥ 65 years of age and in males (p-value = 0.0102).
Conclusions: Lamotrigine users have a significantly higher risk of VT. Males and older patients are particularly at risk for this cardiovascular adverse effect.
Funding: National Institutes of Health grants R01NS121234 and R01HL155378
Anti-seizure Medications