Similarly, a second cohort study involving nearly 12,000 lamotrigine users and 150,000 levetiracetam users reported no significant differences in incidences of ventricular arrhythmia and sudden cardiac arrest.

In 2020, the FDA issued a safety warning regarding lamotrigine, citing concerns that it could increase the risk of heart conditions, particularly in patients with pre-existing heart issues.

Lead researcher Gloria Y.F. Ho highlighted that their real-world data provided insights that contradicted the FDA's initial concerns.

The first cohort study analyzed over 53,000 patients and found no significant difference in new diagnoses of ventricular tachycardia or ventricular fibrillation between lamotrigine and levetiracetam users.

Importantly, no increased risk for ventricular arrhythmia or sudden cardiac arrest was found even in patients with a history of heart disease, which was a key concern of the FDA warning.

It's worth noting that the findings may not apply to younger patients or those without epilepsy, as the studies primarily focused on individuals aged 65 and older.

However, recent studies have challenged this warning, indicating that lamotrigine does not increase cardiac risk in older adults with epilepsy.

This warning was based on limited evidence, including in vitro studies and case reports of arrhythmias, which may not accurately reflect human physiology.

Lamotrigine, marketed as Lamictal, is a widely used first-line therapy for certain types of epilepsy, accounting for about 10% of all antiseizure medication prescriptions in the United States.

The studies were co-authored by researchers including Gloria Ho, Tobias Gerhard, Daniel Horton, and Parin Patel, enhancing the credibility of the findings.

An accompanying editorial reinforced that lamotrigine appears to be safe and effective, aligning with the conclusions of both research teams.

Currently, approximately 2.9 million adults in the U.S. are living with epilepsy, making the safety and efficacy of lamotrigine a significant concern.