An FDA review of study findings showed a potential increased risk of heart rhythm problems, called arrhythmias, in patients with heart disease who are taking the seizure and mental health medicine Lamictal (lamotrigine).

FDA wants to evaluate whether other medicines in the same drug class have similar effects on the heart and are also requiring safety studies on those medicines. FDA will update the public when additional information from these studies becomes available. 

FDA required these studies, called in vitro studies, to further investigate Lamictal’s effects on the heart after FDA received reports of abnormal electrocardiographic (ECG) findings and some other serious problems. In some cases, problems including chest pain, loss of consciousness and cardiac arrest occurred. FDA first added information about this risk to the lamotrigine prescribing information and Medication Guides in October 2020, which has been updated.

Background:

Lamotrigine is used alone or with other medicines to treat seizures in patients 2 years and older. It may also be used as maintenance treatment in patients with the mental health condition bipolar disorder to help delay the occurrence of mood episodes such as depression, mania, or hypomania. 

Recommendations:

Patients should not stop taking your medicine without first talking to your prescriber because stopping lamotrigine can lead to uncontrolled seizures, or new or worsening mental health problems. Contact your health care professional right away or go to an emergency room if you experience an abnormal heart rate or irregular rhythm, or symptoms such as a racing heartbeat, skipped or slow heartbeat, shortness of breath, dizziness, or fainting.

Health care professionals should assess whether the potential benefits of lamotrigine outweigh the potential risk of arrhythmias for each patient. Laboratory testing performed at therapeutically relevant concentrations has shown that lamotrigine can increase the risk of serious arrhythmias, which can be life-threatening in patients with clinically important structural or functional heart disorders. Clinically important structural and functional heart disorders include heart failure, valvular heart disease, congenital heart disease, conduction system disease, ventricular arrhythmias, cardiac channelopathies such as Brugada syndrome, clinically important ischemic heart disease, or multiple risk factors for coronary artery disease. The risk of arrhythmias may increase further if used in combination with other medicines that block sodium channels in the heart. Other sodium channel blockers approved for epilepsy, bipolar disorder, and other indications should not be considered safer alternatives to lamotrigine in the absence of additional information (see List of Sodium Channel Blockers Required to Conduct Postmarket Studies below.

Health professionals and patients are encouraged to report adverse events or side effects related to the use of these products to the FDA's MedWatch Safety Information and Adverse Event Reporting Program.