Mexiletine is a prescription medication that is used to treat severe irregular heartbeat such as persistent ventricular tachycardia. Mexiletine is an antiarrhythmic drug and works by blocking electrical heart signals and affecting the way that the heart works.

Make sure to always read the patient information and instructions before using this medication. Always follow your doctor’s directions.

• The initial dose of mexiletine is typically given in the hospital.
• Taking this medication with food or an antacid can help to prevent stomach upset.
• You may need your heart function checked while taking mexiletine.
• Do not stop taking this medication without speaking to your doctor.

Tell your doctor and pharmacist:

• About your drug and other allergies
• If you take any other prescription or over-the-counter medications
• Your medical history particularly of heart conditions, congestive heart failure, AV block, epilepsy, other seizure disorders, liver disease, or a weak immune system
• If you are pregnant or planning pregnancy

You should also know:

• You should not breast-feed while taking mexiletine.

Common side effects of mexiletine include but are not limited to:

• Nausea or vomiting
• Heartburn
• Dizziness
• Stomach upset
• Tremors or nervousness
• Lightheadedness
• Coordination problems
• Blurred vision

Get medical help if you have any of the following side effects of mexiletine:

• A new or worsening irregular heartbeat
• Chest pain
• Signs of a liver problem such as dark urine, clay-colored stools, jaundice, nausea, itching, tiredness, or upper stomach pain.
• Symptoms of an allergic reaction such as difficulty breathing, hives, or swelling in your face, lips, or throat.

What should I do if I miss a dose of mexiletine?

If you miss a dose of mexiletine, you should take it as soon as you remember. However, if it is almost time for your next dose, then skip your missed dose. Missing doses of this medication can be dangerous.

What is the strength of mexiletine?

Mexiletine is available in strengths of 100mg, 150mg, 200mg and 200mg.