Mexiletine: Uses, Dosage, Side Effects & Important Info

Summary of Key Points

Mexiletine is a medication used to treat certain heart rhythm disorders and some types of nerve pain. It works by stabilizing electrical signals in the heart and reducing abnormal nerve activity. Mexiletine is commonly prescribed for conditions such as ventricular tachycardia and diabetic neuropathy. Always take this medication exactly as prescribed by your healthcare provider, and consult them before making any changes to your dosage.

Names of Medication

US Brand Name: Mexitil

Generic Name: Mexiletine

The generic name refers to the active ingredient in the medication. It is the same as the brand name but may be sold under different names.

Pharmacologic Category

Category: Class I-B Antiarrhythmic

Mexiletine Dosage

Mexiletine is used to treat various conditions. Below are the recommended doses for adults. Always follow your healthcare provider’s instructions and consult them before adjusting your dose. If you need to speak with a provider, you can schedule a telemedicine visit with us today.

Ventricular Tachycardia

Initial Dose: 200 mg orally every 8 hours.

Maintenance Dose: 200-300 mg every 8 hours, depending on response.

Length of Treatment: Long-term use may be necessary to manage symptoms.

Arrhythmia

Initial Dose: 200 mg orally every 8 hours.

Maintenance Dose: 200-300 mg every 8 hours.

Length of Treatment: As directed by your healthcare provider.

Long QT Syndrome

Initial Dose: 200 mg orally every 8 hours.

Maintenance Dose: Adjusted based on response and tolerance.

Length of Treatment: Long-term management may be required.

Idiopathic Ventricular Fibrillation

Initial Dose: 200 mg orally every 8 hours.

Maintenance Dose: 200-300 mg every 8 hours.

Length of Treatment: Long-term use may be necessary to prevent recurrence.

Cardiac Dysrhythmias

Initial Dose: 200 mg orally every 8 hours.

Maintenance Dose: 200-300 mg every 8 hours.

Length of Treatment: As directed by your healthcare provider.

Myotonic Dystrophy

Initial Dose: 150 mg orally every 8-12 hours.

Maintenance Dose: 150-300 mg every 8-12 hours.

Length of Treatment: Long-term use may be necessary to manage symptoms.

Neuropathic Pain (including Diabetic Neuropathy, Postherpetic Neuralgia, Fibromyalgia)

Initial Dose: 150 mg orally every 8-12 hours.

Maintenance Dose: 150-300 mg every 8-12 hours, depending on response.

Length of Treatment: Long-term use may be required to manage chronic pain.

Dosage Forms and Strengths

Capsules: 150 mg, 200 mg, 250 mg

Administration Instructions for Mexiletine

Mexiletine should be taken by mouth, usually with food or an antacid to reduce stomach upset. Swallow the capsule whole with a full glass of water. Do not crush or chew the capsules, as this can release the drug all at once, increasing the risk of side effects. If you miss a dose, take it as soon as you remember unless it is almost time for your next dose. In that case, skip the missed dose and resume your regular schedule. Never double up on doses.

Mexiletine Side Effects and Adverse Reactions

Like all medications, Mexiletine can cause side effects. Some are common and mild, while others are rare but more serious. Always inform your healthcare provider if you experience any side effects. If you have concerns, you can schedule a telemedicine appointment with one of our providers.

Common Side Effects

These occur in more than 1 in 10 patients:

1. Nausea: Feeling sick to your stomach.
2. Heartburn: A burning sensation in your chest or throat.
3. Dizziness: Feeling lightheaded or unsteady.

Less Common Side Effects

These occur in 1 in 100 to 1 in 1,000 patients:

1. Tremors: Shaking or trembling in your hands or other parts of your body.
2. Blurred Vision: Difficulty seeing clearly.
3. Fatigue: Feeling unusually tired or weak.

Rare but Serious Side Effects

These occur in fewer than 1 in 1,000 patients:

1. Severe Allergic Reactions: Swelling of the face, lips, tongue, or throat, difficulty breathing, or severe rash. Seek emergency medical attention immediately.
2. Worsening Heart Rhythm Problems: If you notice new or worsening palpitations, chest pain, or shortness of breath, contact your healthcare provider right away.
3. Liver Problems: Symptoms include yellowing of the skin or eyes (jaundice), dark urine, or severe stomach pain.

Contraindications for Mexiletine

A contraindication is a specific situation or condition where a medication should not be used because it may cause harm. Mexiletine is contraindicated in several situations due to the potential risks. Below is a list of common contraindications for Mexiletine and why it is not recommended in these cases:

Severe Heart Block: Mexiletine is contraindicated in patients with severe heart block (a condition where the electrical signals in the heart are partially or completely blocked) unless a pacemaker is in place. This is because Mexiletine can further slow down the heart’s electrical signals, worsening the condition.

Cardiogenic Shock: Patients in cardiogenic shock (a condition where the heart suddenly can’t pump enough blood to meet the body’s needs) should not take Mexiletine. The medication can further impair heart function and blood circulation.

Hypersensitivity to Mexiletine: If you have had an allergic reaction to Mexiletine or any of its components in the past, you should not take this medication. Allergic reactions can range from mild rashes to severe, life-threatening conditions like anaphylaxis.

Severe Liver Disease: Mexiletine is metabolized by the liver. If you have severe liver disease, your body may not be able to process the medication properly, leading to increased side effects or toxicity.

Drug to Drug Interactions

Mexiletine can interact with other medications, potentially increasing side effects or reducing the effectiveness of either drug. Below are some known interactions with Mexiletine:

1. Quinidine (Quinidex): Taking Mexiletine with Quinidine may raise the levels of both drugs in the bloodstream, heightening the risk of side effects such as dizziness, low blood pressure, and irregular heart rhythms.
2. Phenytoin (Dilantin): Phenytoin may decrease Mexiletine’s effectiveness by accelerating its breakdown in the liver.
3. Theophylline (Theo-24): Mexiletine can increase Theophylline levels in the blood, which may lead to side effects like nausea, vomiting, and seizures.
4. Warfarin (Coumadin): Mexiletine may enhance the effects of Warfarin, increasing the risk of bleeding. Close monitoring of blood clotting times (INR) is recommended when these medications are used together.
5. Cimetidine (Tagamet): Cimetidine can elevate Mexiletine levels in the blood, potentially leading to toxicity.

Mexiletine in Pregnancy

Is it safe to take Mexiletine during pregnancy? The safety of Mexiletine hydrochloride in pregnant women has not been fully established. While animal studies have shown some risks, there is limited data on its effects in humans. Mexiletine should only be used during pregnancy if the potential benefits outweigh the risks. If you are pregnant or planning to become pregnant, consult your healthcare provider to discuss whether Mexiletine is the right option for you. Our telemedicine providers are available to help you make an informed decision.

Mexiletine while Breastfeeding

Is it safe to take Mexiletine while breastfeeding? Mexiletine is excreted in breast milk, but its effects on a nursing infant are not well studied. If you are breastfeeding, discuss the potential risks and benefits with your healthcare provider. In some cases, an alternative medication may be recommended, or you may need to monitor your baby for any signs of side effects. Our telemedicine providers can assist you in evaluating your options.

Estimated Cost of Mexiletine Medication

The estimated cost of a 30-day supply of Mexiletine without insurance ranges from $50 to $150, depending on the dosage and pharmacy. Using a GoodRX coupon can lower the cost, with prices ranging from $30 to $80 for a 30-day supply. Check with your local pharmacy for the most accurate pricing.

Possible Alternatives to Mexiletine

If Mexiletine is not suitable for you, alternative treatments and lifestyle changes may help manage your condition. Always discuss these alternatives with your healthcare provider before making any changes to your treatment plan. Our telemedicine providers are available to guide you through these options.

1. Ventricular Tachycardia: Alternatives include other antiarrhythmic drugs like Amiodarone or Sotalol. In some cases, an implantable cardioverter-defibrillator (ICD) may be recommended.
2. Arrhythmia: Beta-blockers (e.g., Metoprolol) or calcium channel blockers (e.g., Diltiazem) may be used as alternatives. Lifestyle changes, such as reducing caffeine intake and managing stress, can also help.
3. Long QT Syndrome: Beta-blockers are often the first-line treatment. Avoiding medications that prolong the QT interval is also crucial.
4. Idiopathic Ventricular Fibrillation: ICD implantation is often recommended. Medications like Amiodarone may be used in some cases.
5. Cardiac Dysrhythmias: Options include medications like Flecainide or Propafenone. Catheter ablation may be considered for certain types of dysrhythmias.
6. Myotonic Dystrophy: Physical therapy and medications like Phenytoin or Carbamazepine may help manage symptoms.
7. Neuropathic Pain: Alternatives include Gabapentin, Pregabalin, or topical treatments like Lidocaine patches. Lifestyle changes such as regular exercise and stress management may also help.
8. Diabetic Neuropathy: Medications like Duloxetine or Pregabalin are commonly used. Managing blood sugar levels through diet and exercise is also important.
9. Postherpetic Neuralgia: Gabapentin, Pregabalin, and Lidocaine patches are common alternatives. Antidepressants like Amitriptyline may also help.
10. Fibromyalgia: Medications like Duloxetine or Milnacipran may be used. Regular exercise, stress reduction, and cognitive behavioral therapy (CBT) are also effective in managing symptoms.

Recent Updates on Mexiletine Research

Recent research on Mexiletine has focused on its use in treating non-cardiac conditions, such as myotonic dystrophy and neuropathic pain. A 2022 study published in the journal Neurology found that Mexiletine significantly reduced muscle stiffness in patients with myotonic dystrophy, improving their quality of life. Additionally, ongoing clinical trials are exploring Mexiletine’s potential in managing chronic pain conditions like fibromyalgia and diabetic neuropathy. As more data becomes available, Mexiletine may become a more widely used option for these conditions. Always consult your healthcare provider to stay informed about the latest treatment options. Our telemedicine providers are here to help you navigate these updates and make the best decision for your health.

James Kingsley

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