Mexiletine hydrochloride

By Medically reviewed by hellodoktor

Generic Name: Mexiletine hydrochloride Brand Name(s): Generics only. No brands available.


What is mexiletine hydrochloride used for?

Mexiletine is an antiarrhythmic. It works by stabilizing the heart rhythm, which helps to keep the heart from beating too fast or in an irregular rhythm.

Mexiletine hydrochloride is commonly used for treating certain types of a life-threatening irregular heartbeat.

How should I take mexiletine hydrochloride?

Take this medication by mouth with a full glass of water, usually 2 to 3 times daily or exactly as directed by your doctor.

Taking this medication with food or an antacid helps to decrease certain side effects such as nausea or heartburn. Ask your pharmacist if you have questions about which antacids to use with this medication.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day.

Tell your doctor if your condition does not improve or if it worsens.

How do I store mexiletine hydrochloride?

Mexiletine hydrochloride is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store mexiletine hydrochloride in the bathroom or the freezer. There may be different brands of mexiletine hydrochloride that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush mexiletine hydrochloride down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using mexiletine hydrochloride?

Before using this drug, tell your doctor if:

  • You are allergic to any ingredient in mexiletine hydrochloride.
  • You are pregnant, planning to become pregnant, or are breastfeeding.
  • You are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement.
  • You have allergies to medicines, foods, or other substances.

Is it safe during pregnancy or breastfeeding?

There are no adequate studies in women for determining risk when using mexiletine hydrochloride during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking mexiletine hydrochloride. Mexiletine hydrochloride is pregnancy risk category C, according to the US Food and Drug Administration (FDA).

FDA pregnancy risk category reference below:

  • A=No risk
  • B=No risk in some studies
  • C=There may be some risk
  • D=Positive evidence of risk
  • X=Contraindicated
  • N=Unknown

Side effects

What side effects can occur from mexiletine hydrochloride?

When using this drug, some common side effects may occur:

  • Dizziness or lightheadedness
  • Heartburn
  • Nausea and vomiting
  • Nervousness
  • Trembling or shaking of the hands
  • Unsteadiness or difficulty in walking
  • Blurred vision
  • Confusion
  • Constipation or diarrhea
  • Headache
  • Numbness or tingling of fingers and toes
  • Ringing in the ears
  • Skin rash
  • Slurred speech
  • Trouble in sleeping
  • Unusual tiredness or weakness

If any of the following side effects occur while taking mexiletine, check with your doctor or nurse as soon as possible:

  • Anorexia and dyspepsia
  • Fine hand tremor
  • Short-term memory loss
  • Malaise
  • Seizures
  • Loss of consciousness
  • Palpitation and chest pain
  • Syncope
  • Hypotension
  • Hypertension
  • Bradycardia
  • Conduction disturbances
  • Atrial arrhythmias
  • Edema
  • Congestive heart failure
  • A generalized pruritic
  • Erythematous
  • Papular rash
  • Diplopia
  • Nystagmus
  • Psychosis
  • Hallucinations
  • Shortness of breath

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.


What drugs may interact with mexiletine hydrochloride?

Mexiletine hydrochloride may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products may interact with this drug, such as:

  • Aspir 81 (aspirin)
  • Aspirin Low Strength (aspirin)
  • Benadryl (diphenhydramine)
  • Coreg (carvedilol)
  • Coumadin (warfarin)
  • Crestor (rosuvastatin)
  • Cymbalta (duloxetine)
  • Fish Oil (omega-3 polyunsaturated fatty acids)
  • Lasix (furosemide)
  • Lipitor (atorvastatin)
  • Lyrica (pregabalin)
  • Metoprolol Succinate ER (metoprolol)
  • Nexium (esomeprazole)
  • Provigil (modafinil)
  • Sotalol Hydrochloride AF (sotalol)
  • Synthroid (levothyroxine)
  • Vitamin B12 (cyanocobalamin)
  • Vitamin C (ascorbic acid)
  • Vitamin D3 (cholecalciferol)
  • Xanax (alprazolam)

Does food or alcohol interact with mexiletine hydrochloride?

Mexiletine hydrochloride may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with mexiletine hydrochloride?

Mexiletine hydrochloride may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

These health conditions may include:

  • Heart problems (e.g., heart block or AV block, conductions problems)
  • Congestive heart failure
  • A pacemaker
  • Low blood pressure
  • Liver problems
  • A seizure disorder


The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using mexiletine hydrochloride.

What is the dose of mexiletine hydrochloride for an adult?

Ventricular Tachycardia

Initial dose: 200 mg orally every 8 hours when rapid control of arrhythmia is not essential.

A minimum of 2-3 days between dose adjustments is recommended.

Dose may be adjusted in 50 or 100 mg increments up or down.


The recommended dose is 1.4 to 5 mg/kg/dose given every 8 hours.

Begin with lower initial dosages and titrate to desired effects and serum concentrations.

Liver Dose Adjustments

Patients with severe liver disease may require lower doses and must be monitored closely.

Dose Adjustments

Satisfactory control can be achieved in most patients by 200 to 300 mg given orally every 8 hours with food or antacid. If satisfactory response has not been achieved at 300 mg every 8 hours, a dose of 400 mg every 8 hours may be tried.

When rapid control of ventricular arrhythmia is essential, an initial loading dose of 400 mg of mexiletine may be administered, followed by a 200 mg dose in eight hours.

What is the dose of mexiletine hydrochloride for a child?

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is mexiletine hydrochloride available?

Mexiletine hydrochloride is available in the following dosage forms and strengths:

  • Capsule 50 mg, 150 mg, 200 mg, 250 mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of mexiletine hydrochloride, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

msBahasa Malaysia

Review Date: April 10, 2017 | Last Modified: September 13, 2019