Description

Mexiletine Hydrochloride Capsules – 50mg 100mg 200mg

Prescription Antiarrhythmic Medicine

Mexiletine Hydrochloride Capsules are prescription Class Ib antiarrhythmic medicines available in 50mg, 100mg and 200mg strengths. Mexiletine works mainly by blocking cardiac sodium channels, helping suppress certain abnormal electrical impulses originating in the ventricles of the heart. In the UK product information, mexiletine is indicated for documented ventricular arrhythmias considered life-threatening by the treating physician. Treatment should be initiated and monitored by a specialist experienced in managing cardiac arrhythmias.

Prescription required

Mexiletine Hydrochloride 50mg, 100mg and 200mg hard capsules contain the antiarrhythmic medicine mexiletine hydrochloride. Mexiletine is a Class Ib antiarrhythmic agent used for documented ventricular arrhythmias considered life-threatening. It reduces abnormal ventricular electrical activity primarily through inhibition of inward sodium current in cardiac cells. Treatment requires individualised dosing and specialist medical supervision.

What Are Mexiletine Hydrochloride Capsules?

Mexiletine Hydrochloride Capsules are an oral Class Ib antiarrhythmic medicine containing mexiletine hydrochloride.

Mexiletine is structurally and pharmacologically related to lidocaine and acts on the electrical activity of cardiac cells.

In UK prescribing information, mexiletine is indicated for the treatment of documented ventricular arrhythmias that a physician considers life-threatening. It should not be viewed as a general treatment for palpitations or every type of irregular heartbeat.

Treatment with mexiletine should be initiated and monitored by a specialist experienced in treating cardiac arrhythmias.

Available strengths include:

• Mexiletine Hydrochloride 50mg Capsules
• Mexiletine Hydrochloride 100mg Capsules
• Mexiletine Hydrochloride 200mg Capsules

Different strengths allow a specialist to individualise treatment according to the patient’s clinical response, tolerance and prescribed dosage.

How Does Mexiletine Work? – Mechanism of Action

Mexiletine is a Class Ib sodium-channel-blocking antiarrhythmic.

Electrical impulses in the heart depend partly on sodium moving through specialised channels in cardiac cells. Mexiletine inhibits the inward sodium current and reduces the rate of rise of phase 0 of the cardiac action potential.

In practical terms, this action can help suppress abnormal electrical activity originating in the ventricles and reduce certain ventricular arrhythmias.

Mexiletine does not simply “slow the heart”. Its electrophysiological effects are more specific, which is one reason treatment requires specialist assessment and monitoring.

What Is Mexiletine Used For?

Mexiletine Hydrochloride Capsules are indicated for the treatment of documented ventricular arrhythmias considered life-threatening by the treating physician.

Ventricular arrhythmias are abnormal heart rhythms originating in the lower chambers of the heart, known as the ventricles.

Mexiletine should only be used when specifically prescribed for the individual patient. Class I antiarrhythmic medicines have not been shown to improve survival in patients with ventricular arrhythmias, and mexiletine has pro-arrhythmic potential. Appropriate patient selection and specialist monitoring are therefore essential.

Mexiletine Hydrochloride 50mg Capsules

Mexiletine Hydrochloride 50mg Capsules provide a lower capsule strength that may be used as part of an individually prescribed dosing regimen.

Dose selection and adjustment must be determined by the treating specialist. Patients should not increase, decrease or combine capsule strengths without medical instructions.

Mexiletine Hydrochloride 100mg Capsules

Mexiletine Hydrochloride 100mg Capsules contain 100mg of mexiletine hydrochloride per capsule and may be incorporated into a patient’s individual antiarrhythmic treatment regimen.

The appropriate dose depends on factors including treatment response, tolerance, other medicines and relevant medical conditions.

Mexiletine Hydrochloride 200mg Capsules

Mexiletine Hydrochloride 200mg Capsules provide a higher capsule strength for patients whose prescribed regimen requires it.

The 200mg strength should not be substituted for another strength or used to alter a prescribed dose without instructions from the treating clinician.

Benefits of Mexiletine Hydrochloride Capsules

When prescribed for an appropriate patient, mexiletine can help suppress certain serious ventricular arrhythmias.

Potential therapeutic benefits include:

• Suppression of abnormal ventricular electrical activity
• Reduction of certain ventricular arrhythmias
• Oral administration for patients requiring ongoing antiarrhythmic treatment
• Availability of 50mg, 100mg and 200mg strengths to facilitate individualised dosing

The expected benefit and potential risks should be assessed by the specialist responsible for treatment.

How to Take Mexiletine Hydrochloride Capsules

Always take mexiletine exactly as prescribed by your doctor or specialist.

Mexiletine capsules are for oral use and should generally be swallowed whole with sufficient liquid while upright.

Taking mexiletine with food is advisable because this may help minimise gastrointestinal adverse effects.

Your dosage is individually determined according to your condition, response and tolerance. Do not alter your dose, stop treatment, or change between the 50mg, 100mg and 200mg strengths unless instructed by your healthcare professional.

If you miss a dose or accidentally take more than prescribed, consult the patient information leaflet and obtain advice from your doctor, pharmacist or appropriate urgent medical service.

Side Effects of Mexiletine

Like all medicines, mexiletine can cause side effects, although not everybody experiences them.

Reported adverse effects include:

• Dizziness
• Tremor
• Abdominal pain
• Indigestion or dyspepsia
• Nausea
• Headache
• Constipation
• Dry mouth
• Tiredness or weakness
• Blurred vision
• Tingling or altered sensation
• Palpitations
• Changes in heart rhythm
• Low blood pressure
• Rash

Serious reactions can occur, including worsening or new cardiac arrhythmias, severe allergic or skin reactions, blood-cell abnormalities and liver injury.

Seek urgent medical attention if you develop severe or worsening heart symptoms, fainting, significant breathing difficulty, a severe skin reaction, facial/throat swelling, or other symptoms suggesting a serious reaction.

Always read the supplied Patient Information Leaflet for the complete adverse-effect and safety information.

Cautions and Important Safety Information

Mexiletine is a specialist antiarrhythmic medicine and is not appropriate for every patient with an irregular heartbeat.

Tell your doctor or pharmacist about your complete medical history and all medicines you take before starting treatment.

Particular caution or specialist assessment may be necessary in people with:

• Heart failure or low blood pressure
• Cardiac conduction abnormalities
• A history of seizures
• Liver impairment
• Kidney impairment
• Electrolyte disturbances
• Blood disorders
• Pregnancy or breastfeeding
• Known sensitivity to mexiletine or amide-type local anaesthetics

Mexiletine can interact with other medicines, including other antiarrhythmics and medicines affecting its metabolism.

Smoking can also affect mexiletine pharmacokinetics. Tell your healthcare professional if you start or stop smoking while taking mexiletine.

Mexiletine may cause neurological effects such as dizziness, tremor or blurred vision that can impair driving or operating machinery. Alcohol may further impair these abilities.

Do not stop mexiletine suddenly or alter your prescribed dosage without consulting your treating clinician.

Mexiletine Veterinary Use – Important Information for Dog Owners and Veterinary Professionals

Mexiletine is an oral Class Ib antiarrhythmic medicine that veterinary surgeons may use in selected dogs with ventricular arrhythmias. In veterinary cardiology, mexiletine may be considered for conditions involving abnormal electrical activity originating in the ventricles, including certain ventricular premature complexes and ventricular tachyarrhythmias.

Human Mexiletine Hydrochloride Capsules should not automatically be described as authorised veterinary medicines. In Great Britain, a veterinary surgeon may prescribe a human-authorised medicine under the veterinary prescribing cascade when the applicable legal and clinical requirements are satisfied.

Veterinary prescription and veterinary assessment required for use in animals. Never administer human-prescribed mexiletine to a dog without veterinary instructions.

What Is Mexiletine Used for in Dogs?

Mexiletine is an oral Class Ib antiarrhythmic medicine that may be used by veterinary surgeons in selected dogs with ventricular rhythm disturbances.

A ventricular arrhythmia occurs when abnormal electrical impulses originate within the ventricles—the lower pumping chambers of the heart.

Depending on the individual dog’s diagnosis, a veterinary cardiologist may consider mexiletine as part of the management of certain:

• Ventricular arrhythmias
• Ventricular premature complexes (VPCs/PVCs)
• Ventricular tachyarrhythmias
• Ventricular tachycardia
• Other clinically significant ventricular rhythm disturbances

The presence of an abnormal heartbeat does not automatically mean mexiletine is appropriate. The underlying cause, type and severity of the arrhythmia must first be established by a veterinary professional.

Medical & Pharmacy Information

This product information is designed to provide clear, evidence-based medicine information and does not replace individual medical advice.

Mexiletine is a prescription-only antiarrhythmic medicine requiring appropriate diagnosis, specialist prescribing and monitoring. Product information should be interpreted alongside the current Summary of Product Characteristics (SmPC), Patient Information Leaflet (PIL) and advice from the treating clinician and dispensing pharmacist.

For veterinary use, prescribing decisions must be made by an appropriately qualified veterinary surgeon in accordance with applicable veterinary medicines legislation and professional requirements

Frequently Asked Questions About Mexiletine Hydrochloride Capsules

1. What is Mexiletine Hydrochloride used for?

Mexiletine is a Class Ib antiarrhythmic medicine. UK prescribing information indicates it for documented ventricular arrhythmias that, in the judgement of the treating physician, are considered life-threatening.

2. What strengths of Mexiletine Hydrochloride Capsules are available?

Mexiletine Hydrochloride hard capsules are available in 50mg, 100mg and 200mg strengths, allowing specialists to construct an individualised dosing regimen.

3. How does Mexiletine work?

Mexiletine primarily blocks inward sodium current in cardiac cells. This changes cardiac electrical activity and can suppress certain abnormal ventricular rhythms.

4. Is Mexiletine a beta blocker?

No. Mexiletine is not a beta blocker. It is classified as a Class Ib antiarrhythmic sodium-channel blocker.

5. Are Mexiletine 50mg, 100mg and 200mg Capsules prescription-only?

Yes. Mexiletine requires medical prescribing and specialist supervision.

Prescription required – pharmacist review included.

6. How should I take Mexiletine Capsules?

Take mexiletine exactly as prescribed. The capsules are taken orally and should be swallowed whole with sufficient liquid. Taking them with food is advisable to help minimise gastrointestinal adverse effects.

7. Can I change from Mexiletine 50mg to 100mg or 200mg myself?

No. Do not change strengths or alter your dosage without instructions from the healthcare professional managing your treatment. Mexiletine dosing must be individualised.

8. What are the common side effects of Mexiletine?

Side effects can include dizziness, tremor, gastrointestinal discomfort, nausea, headache, constipation, tiredness, blurred vision and other neurological or cardiovascular effects. Consult the Patient Information Leaflet for the complete list.

9. Can Mexiletine make an abnormal heart rhythm worse?

Potentially. Like other antiarrhythmic medicines, mexiletine has pro-arrhythmic potential, meaning it can sometimes cause or worsen abnormal heart rhythms. This is an important reason it requires specialist prescribing and monitoring.

10. Can Mexiletine be used for ventricular tachycardia?

Mexiletine may be used in specialist management of certain serious ventricular arrhythmias. Whether it is appropriate for ventricular tachycardia in an individual patient must be determined by a cardiac specialist.

11. Can Mexiletine be used in dogs?

Mexiletine has veterinary applications, particularly in specialist management of certain canine ventricular arrhythmias. However, a human mexiletine product should not be given to an animal unless specifically prescribed by a veterinary surgeon.

12. What is Mexiletine used for in dogs?

Veterinary surgeons may use mexiletine as an oral antiarrhythmic in selected dogs with ventricular rhythm disorders, including certain ventricular tachyarrhythmias. The diagnosis, dose and monitoring requirements must be determined by the treating veterinarian.

13. Is Mexiletine an authorised veterinary medicine in the UK?

Do not assume that a human Mexiletine Hydrochloride Capsule is an authorised veterinary medicine. In appropriate circumstances, a veterinary surgeon may prescribe a human-authorised medicine under the UK’s veterinary prescribing cascade when the relevant regulatory conditions are satisfied.

14. Can I give my prescribed Mexiletine Capsules to my dog?

No. Never share your prescription medicine with an animal. Veterinary dosing cannot be safely determined from a human prescription. A veterinarian must assess the animal and prescribe the appropriate treatment.

15. Does a dog taking Mexiletine need monitoring?

Veterinary patients treated for significant cardiac arrhythmias may require ongoing veterinary assessment and cardiac monitoring. The exact monitoring schedule depends on the animal’s condition and should be determined by the treating veterinary surgeon.

16. Should Mexiletine be taken with food?

UK product information advises taking Mexiletine Hard Capsules with food to help minimise gastrointestinal adverse effects.

17. Can I drive while taking Mexiletine?

Mexiletine can cause central nervous system effects that may impair your ability to drive or operate machinery. Do not drive if you experience symptoms that affect alertness, judgement, vision or coordination.

18. Can I stop taking Mexiletine when my heart rhythm improves?

Do not discontinue or alter prescribed mexiletine treatment without speaking to your specialist. Your treatment plan is based on your underlying arrhythmia and clinical response.

19. Who should prescribe and monitor Mexiletine treatment?

UK prescribing information states that treatment should be initiated and monitored by a specialist experienced in treating cardiac arrhythmias.

20. What should I tell my doctor before taking Mexiletine?

Tell your doctor about heart conditions, low blood pressure, liver or kidney problems, seizures, blood disorders, pregnancy or breastfeeding, smoking status, allergies and all prescription, non-prescription and complementary medicines you use.

Important: This information does not replace the Patient Information Leaflet, Summary of Product Characteristics, medical consultation or veterinary advice. Human and veterinary use are separate prescribing contexts.

Mexiletine is a sodium-channel-blocking Class Ib antiarrhythmic with recognised applications in veterinary cardiology. Veterinary surgeons may prescribe mexiletine for selected dogs requiring management of certain ventricular arrhythmias, including some ventricular tachyarrhythmias.

Treatment is individualised according to the dog’s diagnosis, clinical condition, concurrent medication and veterinary assessment. Veterinary patients receiving mexiletine may require ECG and other cardiac monitoring.

A human Mexiletine Hydrochloride Capsule should not be assumed to be a licensed veterinary medicine. Veterinary use must be prescribed and supervised by a veterinary surgeon in accordance with applicable medicines regulations.