Rationale: Lamotrigine, a commonly prescribed antiseizure medication, has known sodium channel-blocking effects that may influence cardiac conduction. Veterans with epilepsy may be at heightened risk due to coexisting cardiovascular disease and polypharmacy. Furthermore, those with epilepsy may also be particularly vulnerable due to interactions between epilepsy, seizures, and the cardiovascular system. Evaluating lamotrigine’s impact on cardiac conduction in this population is critical to understanding potential risks.
Methods:
Subjects were identified through review of admissions to the Epilepsy Monitoring Unity (EMU) at the William S Middleton Memorial Veterans Hospital between 2018 and 2021. Inclusion criteria included a diagnosis of epilepsy, treatment with lamotrigine during the admission, changes to the lamotrigine dose during admission, and EKG monitoring within the EMU recording. Clinical data including age, sex, comorbid medical conditions, medications in addition to lamotrigine, and timing and dose of lamotrigine during admission was acquired.
Results:
A total of 23 patients were identified, 5 women and 18 men. Average EKG recording covered 88.4 hours. Lamotrigine doses ranged from 25mg to 400mg. Review of cardiac conduction including RR interval, the PR interval, QRS duration, and QTc interval did not demonstrate variation correlated with lamotrigine dose or time since lamotrigine dose. Cardiac conduction parameters were analyzed both within patients as well as effects from sex, co-morbid cardiovascular disease for the group.
Conclusions:
This study provides evidence to support that lamotrigine does not significantly alter cardiac conduction in this population of Veterans with epilepsy, including in patients with comorbid cardiovascular disease.
Funding: None.