Medically reviewed by Drugs.com. Last updated on Mar 7, 2022.
Considering the known proarrhythmic properties of mexiletine and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of mexiletine as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmia .
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antiarrhythmic, Group IB
Chemical Class: Ethylamine
Uses for mexiletine
Mexiletine belongs to the group of medicines known as antiarrhythmics. It is used to correct irregular heartbeats to a normal rhythm.
Mexiletine produces its helpful effects by slowing nerve impulses in the heart and making the heart tissue less sensitive.
Mexiletine is available only with your doctor's prescription.
Before using mexiletine
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For mexiletine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to mexiletine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Studies on mexiletine have been done only in adult patients, and there is no specific information comparing use of mexiletine in children with use in other age groups.
Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of mexiletine in the elderly with use in other age groups.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking mexiletine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using mexiletine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using mexiletine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using mexiletine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using mexiletine with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use mexiletine, or give you special instructions about the use of food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of mexiletine. Make sure you tell your doctor if you have any other medical problems, especially:
- Congestive heart failure or
- Low blood pressure—Mexiletine may make these conditions worse
- Heart attack (severe) or
- Liver disease—Effects may last longer because of slower removal of mexiletine from the body
- Seizures (history of)—Mexiletine can cause seizures
Proper use of mexiletine
Take mexiletine exactly as directed by your doctor, even though you may feel well. Do not take more medicine than ordered.
To lessen the possibility of stomach upset, mexiletine should be taken with food or immediately after meals or with milk or an antacid.
Mexiletine works best when there is a constant amount in the blood. To help keep this amount constant, do not miss any doses. Also it is best to take the doses at evenly spaced times day and night. For example, if you are to take 3 doses a day, the doses should be spaced about 8 hours apart. If this interferes with your sleep or other daily activities, or if you need help in planning the best times to take your medicine, check with your health care professional.
The dose of mexiletine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of mexiletine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (capsules):
- For irregular heartbeat (arrhythmias):
- Adults—At first, 200 milligrams (mg) every eight hours. Then, your doctor may raise or lower your dose as needed.
- Children—Use and dose must be determined by your doctor.
- For irregular heartbeat (arrhythmias):
If you miss a dose of mexiletine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Precautions while using mexiletine
It is important that your doctor check your progress at regular visits to make sure the medicine is working properly. This will allow for changes to be made in the amount of medicine you are taking, if necessary.
Your doctor may want you to carry a medical identification card or bracelet stating that you are using mexiletine.
Before having any kind of surgery (including dental surgery) or emergency treatment, tell the medical doctor or dentist in charge that you are taking mexiletine.
Mexiletine may cause some people to become dizzy, lightheaded, or less alert than they are normally. Make sure you know how you react to mexiletine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.
Mexiletine side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur:
- Chest pain
- fast or irregular heartbeat
- shortness of breath
- Convulsions (seizures)
- fever or chills
- unusual bleeding or bruising
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- Dizziness or lightheadedness
- nausea and vomiting
- trembling or shaking of the hands
- unsteadiness or difficulty in walking
- Blurred vision
- constipation or diarrhea
- numbness or tingling of fingers and toes
- ringing in the ears
- skin rash
- slurred speech
- trouble in sleeping
- unusual tiredness or weakness
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about mexiletine
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- Drug class: group I antiarrhythmics
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