mexiletine
Brand names: Mexitil
Mexiletine is a medicine used to treat life-threatening heart rhythm problems. It helps to stabilize your heartbeat.
Drug Pricing (NADAC)
Generic Price
$0.27/unit
Generic Available
Yes (8 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Mexiletine is used to treat serious, life-threatening ventricular arrhythmias, like sustained ventricular tachycardia.
Common side effects
Nausea, Vomiting, Heartburn
Key warnings
Mexiletine may increase the risk of death or cardiac arrest in some patients with a history of heart attack.
How It Works
Mexiletine belongs to a class of drugs called antiarrhythmics. It works by slowing down the electrical signals in your heart. This helps to make your heartbeat more regular.
How to Take It
Take mexiletine with food or an antacid. If you don't need rapid control of your arrhythmia, start with 200 mg every 8 hours. Your doctor may adjust your dose every 2-3 days by 50-100 mg. Most people take between 200 to 300 mg every 8 hours.
Pregnancy & Breastfeeding
Tell your doctor if you are pregnant or plan to become pregnant. The effects of mexiletine during pregnancy are not fully known. Talk to your doctor about the risks and benefits of taking this medicine while pregnant or breastfeeding.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
Storage
Store mexiletine capsules at room temperature, away from light and moisture.
Side Effects (from patient reports)
Based on 262 FDA adverse event reports.
FDA Adverse Event Report Analysis
Detailed analysis of 408 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.
Total Reports
408
Death-Related Reports
75
Hospitalization Reports
253
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DRUG INEFFECTIVE | 42 |
| 2 | FATIGUE | 31 |
| 3 | VENTRICULAR TACHYCARDIA | 31 |
| 4 | DYSPNOEA | 26 |
| 5 | NAUSEA | 24 |
| 6 | POOR QUALITY SLEEP | 24 |
| 7 | IMPAIRED WORK ABILITY | 23 |
| 8 | IMPAIRED QUALITY OF LIFE | 22 |
| 9 | PYREXIA | 22 |
| 10 | CARDIAC FAILURE | 18 |
| 11 | HYPERTENSION | 18 |
| 12 | PNEUMONIA | 18 |
| 13 | CONTUSION | 15 |
| 14 | ALANINE AMINOTRANSFERASE INCREASED | 14 |
| 15 | CARDIAC FAILURE CONGESTIVE | 14 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Mexiletine may increase the risk of death or cardiac arrest in some patients with a history of heart attack. It should only be used for life-threatening ventricular arrhythmias. This medicine can also cause liver problems, especially if you have congestive heart failure or ischemia.
Known Drug Interactions
Drug Interactions Antiarrhythmic Drugs LIDODERM should be used with caution in patients receiving Class I antiarrhythmic drugs (such as tocainide and mexiletine) since the toxic effects are additive and potentially synergistic.
Mechanism: These drugs have similar effects on the body, so taking them together can cause their toxic side effects to build up. This makes the risk of a bad reaction much higher than taking just one.
What to do: Your doctor should use caution and may need to adjust your dosages. Tell your healthcare provider right away if you feel dizzy or notice changes in your heartbeat.
A variety of antiarrhythmics such as quinidine or propranolol were also added, sometimes with improved control of ventricular ectopy. ECG intervals (PR, QRS, and QT) were not affected by concurrent mexiletine and digoxin, diuretics, or propranolol.
Mechanism: These two heart medicines can be used together to help control irregular heartbeats without changing the heart's electrical timing.
What to do: Your doctor may combine these drugs to better manage your heart rhythm, but they will likely monitor your heart's activity.
ECG intervals (PR, QRS, and QT) were not affected by concurrent mexiletine and digoxin, diuretics, or propranolol. Mexiletine does not alter serum digoxin levels but magnesium-aluminum hydroxide, when used to treat gastrointestinal symptoms due to mexiletine, has been reported to lower serum digoxin levels.
Mechanism: Mexiletine does not change the amount of digoxin in your blood or affect the heart's electrical signals when taken together.
What to do: These medications are generally safe to take together, but you should still follow your doctor's regular monitoring plan for your heart condition.
In another formal study (n = 8 extensive and n = 7 poor metabolizers of CYP2D6), coadministration of propafenone did not alter the kinetics of mexiletine in the poor CYP2D6 metabolizer group. In this crossover steady state study, the pharmacokinetics of propafenone were unaffected in either phenotype by the coadministration of mexiletine. Addition of mexiletine to propafenone did not lead to further electrocardiographic parameters changes of QRS, QT c , RR, and PR intervals than propafenone alone.
Mechanism: These two drugs do not appear to interfere with how the body processes either medication. They also do not cause extra changes to the heart's electrical activity when used together.
What to do: No specific dose changes are usually needed for this combination. Your doctor will monitor your heart health as they normally would.
Concurrent use of mexiletine and theophylline may lead to increased plasma theophylline levels. One controlled study in eight normal subjects showed a 72% mean increase (range 35 to 136%) in plasma theophylline levels. Theophylline plasma levels returned to pre-mexiletine values within 48 hours after discontinuing mexiletine.
Mechanism: Mexiletine can slow down the removal of theophylline from your body, which makes the amount of theophylline in your blood go up.
What to do: Your doctor should check your theophylline blood levels frequently. The dose of theophylline may need to be reduced to avoid side effects.
Common Questions
Can I take mexiletine if I have a pacemaker?
What should I do if I experience side effects?
Can I drink alcohol while taking mexiletine?
Will mexiletine cure my arrhythmia?
How long will I need to take mexiletine?
Can I stop taking mexiletine on my own?
Does mexiletine interact with other medications?
Can I drive while taking mexiletine?
What is the best time of day to take mexiletine?
How will I know if mexiletine is working?
What are the common side effects of mexiletine?
Does mexiletine interact with other medications?
What drug class is mexiletine?
Is mexiletine safe during pregnancy?
Related Medications in Class IB Antiarrhythmic
Other drugs grouped near mexiletine — same-class peers and common alternatives.
adenosine
Adenocard
Adenosine (Adenocard) is a medicine used to treat certain types of irregular heartbeats.
Compare with mexiletine →
amiodarone
Cordarone, Pacerone
Amiodarone (Pacerone) is a medicine used to treat life-threatening, irregular heartbeats.
Compare with mexiletine →
atropine
AtroPen
Atropine is a medicine that can temporarily block severe effects on your body.
Compare with mexiletine →
bumetanide
Bumex
Bumetanide is a water pill (diuretic).
Compare with mexiletine →
carvedilol
Coreg
Carvedilol is a medicine that lowers blood pressure and helps your heart work better.
Compare with mexiletine →
Medication Guides
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What the FDA Data Shows for mexiletine
The FDA label for mexiletine (sold under brand names such as Mexitil) classifies it as a prescription-only medication in the Class IB Antiarrhythmic class. Mexiletine is used to treat serious, life-threatening ventricular arrhythmias, like sustained ventricular tachycardia. Official labeling lists 7 commonly reported side effects, including Nausea, Vomiting, Heartburn.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 262 voluntary reports. The database also lists 14 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.27.
Report counts do not establish causation — a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice — always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: January 15, 2024
Read our methodology — how this data is sourced, computed, and verified.
All federal data sources used on this page
- FDA Orange Book — approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed — NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) — post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm — standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files — federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database — current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages