• Home
  • Store
    • Newsletter Subscriptions
    • Multimedia Subscriptions
    • Books
    • eBooks
    • ABPN SA Courses
  • CME Center
  • Multimedia
    • Podcast
    • Webinars
    • Blog
  • Newsletters
    • General Psychiatry
    • Child Psychiatry
    • Addiction Treatment
    • Hospital Psychiatry
    • Geriatric Psychiatry
  • Log In
  • Register
  • Welcome
  • Sign Out
  • Subscribe
Home » In Brief: Lamotrigine Gets a New Warning

In Brief: Lamotrigine Gets a New Warning

May 4, 2021
Chris Aiken, MD, and Sarah Rivelli, MD.
From The Carlat Psychiatry Report
Issue Links: Learning Objectives | Editorial Information | PDF of Issue
Chris Aiken, MD, and Sarah Rivelli, MD. Dr. Aiken and Dr. Rivelli have disclosed no relevant financial or other interests in any commercial companies pertaining to this educational activity.

A new warning now sits beneath the list of life-threatening allergic reactions that can happen with lamotrigine. The anticonvulsant is suspected of causing cardiac arrhythmias in susceptible patients by slowing ventricular conduction and widening the QRS. A similar warning has long been in effect with carbamazepine, and both drugs are thought to exert this effect through sodium channel blockade. The problem is distinct from QTc prolongation, another cause of arrhythmias, which is seen with antidepressants and antipsychotics but not with lamotrigine (Rudd GD and Sake JK, Br J Clin Pharmacol 2011;71(6):963).


The American Epilepsy Society pushed back against the labeling, citing a lack of clinical support for the warning, which was based on two in-vitro studies. However, I counted six case reports of ventricular arrhythmias on lamotrigine, and the problem is well documented in lamotrigine overdose (Dream A et al, Am J Emerg Med 2018;36(7):1324.e1–1324.e2). While that suggests the risk is real, it is likely uncommon, considering lamotrigine has been in widespread use since 1994.


The original warning from October 2020 advised clinicians to “avoid” lamotrigine in at-risk patients. Last month, the FDA lightened the language to recommend weighing the risks and benefits, in line with carbamazepine’s labeling. Patients most in need of this risk-benefit consideration are those with cardiac conduction disorders (second- or third-degree heart block, bundle-branch blocks), ventricular arrhythmias, heart failure, ischemic or structural heart disease, and sodium channel disorders (eg, Brugada syndrome). Combining lamotrigine with other sodium channel blockers, such as carbamazepine, would be expected to increase risk for conduction delay.


TCPR’S TAKE: Lithium, carbamazepine, the antipsychotics, and now lamotrigine all carry warnings about cardiac arrhythmias, leaving valproate (Depakote) as the only mood stabilizer unmarked by this risk. No one is recommending routine EKGs before starting lamotrigine, but if your patient has known cardiac conduction delay or significant ischemic or structural heart disease, a friendly consultation with a cardiologist is advised.

General Psychiatry
KEYWORDS antipsychotics carbamazepine lamotrigine
Chris Aiken, MD,

More from this author
Sarah Rivelli, MD.

Does Abortion Lead to Psychiatric Issues?

More from this author
www.thecarlatreport.com
Issue Date: May 4, 2021
SUBSCRIBE NOW
Table Of Contents
CME Post-Test - Problems with Generics, TCPR, May 2021
In Brief: Lamotrigine Gets a New Warning
A Review of Medications for PTSD, With a Focus on Topiramate
What’s Wrong With Generics?
Depression, Vitamin D, and COVID-19
Maintenance Pharmacotherapy of Bipolar Disorder: How Long Is Long Enough?
DOWNLOAD NOW
Featured Book
  • MFB6eCover.jpg

    Medication Fact Book for Psychiatric Practice, Sixth Edition (2022)

    Guidance, clinical pearls, and bottom-line assessments covering the medications you use in your...
    READ MORE
Featured Video
  • therapist_canstockphoto9201097.jpg
    General Psychiatry

    Using SAMe In Clinical Practice with Garrett Rossi, MD

    Read More
Featured Podcast
  • canstockphoto4921771.jpg
    General Psychiatry

    Psychopharm Commandment #6: MAOIs

    MAOIs rank high in efficacy and are pretty well tolerated too, as long as you watch for two critical interactions.

    Listen now
Recommended
  • Approaches to Autism Intervention

    January 31, 2022
    canstockphoto2240982_child-bubbles_thumb.jpg
  • Currently Available Cannabis Products

    September 1, 2022
  • Interpreting Assessment Discrepancies from Multiple Sources

    October 17, 2022
    ChildAssessment.png
  • Approaches to Autism Intervention

    January 31, 2022
    canstockphoto2240982_child-bubbles_thumb.jpg
  • Currently Available Cannabis Products

    September 1, 2022
  • Interpreting Assessment Discrepancies from Multiple Sources

    October 17, 2022
    ChildAssessment.png
  • Approaches to Autism Intervention

    January 31, 2022
    canstockphoto2240982_child-bubbles_thumb.jpg
  • Currently Available Cannabis Products

    September 1, 2022
  • Interpreting Assessment Discrepancies from Multiple Sources

    October 17, 2022
    ChildAssessment.png

About

  • About Us
  • CME Center
  • FAQ
  • Contact Us

Shop Online

  • Newsletters
  • Multimedia Subscriptions
  • Books
  • eBooks
  • ABPN Self-Assessment Courses

Newsletters

  • The Carlat Psychiatry Report
  • The Carlat Child Psychiatry Report
  • The Carlat Addiction Treatment Report
  • The Carlat Hospital Psychiatry Report
  • The Carlat Geriatric Psychiatry Report

Contact

info@thecarlatreport.com

866-348-9279

PO Box 626, Newburyport MA 01950

Follow Us

Please see our Terms and Conditions, Privacy Policy, Subscription Agreement, Use of Cookies, and Hardware/Software Requirements to view our website.

© 2023 Carlat Publishing, LLC and Affiliates, All Rights Reserved.