Mexitil (generic: mexiletine) 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.

*Brand name Mexitil capsules are no longer available. Generic versions are made available by several manufacturers.