Mexitil treats serious arrhythmias (irregular heartbeats). Take with food or an antacid to prevent stomach upset.

Mexitil Overview


Mexitil is a prescription medication used to treat certain types of life-threatening, ventricular arrhythmias (irregular heartbeats). This medication belongs to a group of drugs called Class IB antiarrhythmics which work by blocking sodium channels in the heart, slowing down electrical signals to stabilize heart rhythm.

Mexitil comes in capsule form. It is usually taken 3 times daily, every 8 hours. Sometimes it must be taken twice daily, every 12 hours. Take Mexitil with food or an antacid to prevent stomach upset. 

Common side effects include poor upset stomach, lightheadedness, and dizziness. Do not drive or operate heavy machinery until you know how it affects you.

Patient Ratings for Mexitil

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  • Other
  • Arrhythmias, Cardiac
  • Diabetic Neuropathies
  • Ventricular Fibrillation
  • Ventricular Premature Complexes

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Mexitil Cautionary Labels


Uses of Mexitil

Mexitil is a prescription medication used to treat life-threatening, ventricular arrhythmias (irregular heartbeats).

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.


For more information on this medication choose from the list of selections below.

Mexitil Drug Class

Mexitil is part of the drug class:

Side Effects of Mexitil

Common side effects include:

  • nausea
  • vomiting
  • heartburn
  • changes in appetite
  • lightheadedness or dizziness
  • shaking of a part of your body that you cannot control
  • loss of coordination
  • numbness or tingling sensation
  • headache
  • blurred vision
  • nervousness
  • difficulty speaking
  • swelling of the hands, feet, ankles, or lower legs
  • rash

This is not a complete list of Mexitil side effects. Ask your doctor or pharmacist for more information.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.


Mexitil FDA Warning


Mortality: In the National Heart, Lung and Blood Institute's Cardiac Arrhythmia Suppression Trial (CAST), a long-term, multicentered, randomized, double-blind study in patients with asymptomatic non-life-threatening ventricular arrhythmias who had a myocardial infarction more than six days but less than two years previously, an excessive mortality or non-fatal cardiac arrest rate (7.7%) was seen in patients treated with encainide or flecainide compared with that seen in patients assigned to carefully matched placebo-treated groups (3.0%). The average duration of treatment with encainide or flecainide in this study was ten months.

The applicability of the CAST results to other populations (e.g., those without recent myocardial infarction) is uncertain. Considering the known proarrhythmic properties of Mexitil and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of Mexitil as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmia.