Mexiletine - Oral

Mexiletine is used to treat irregular or abnormal heartbeat.

This medicine may be used to treat other conditions as decided by your doctor.

Take Mexiletine exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.

Take this medicine together with food or immediately after a meal to reduce any stomach discomfort that it may cause. Try to take it at the same time each day.

Swallow the capsule whole with a glass of water, preferably in an upright position.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on the type of your condition and your response to the medication.

Mexiletine must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.

Alert your doctor if you have the following conditions:

• cardiogenic shock (a serious sudden condition when the heart cannot supply enough oxygen-rich blood to the brain and vital organs of the body)
• 2nd- or 3rd-degree heart block, particularly if without a pacemaker (device implanted in the chest that helps control your heartbeat)

as Mexiletine may not be suitable for you.

Inform your doctor if you have the following conditions:

• other heart problems e.g. heart failure (weakness and inability of the heart to pump blood), recent heart attack, 1st-degree heart block
• low blood pressure
• current or history of epilepsy (fits or seizures)
• liver disease

Let your doctor know if you are pregnant or breastfeeding.

Do not switch between different brands unless instructed by your doctor. This is because different brands of Mexiletine may have slightly different ways of working in your body.

Why is it important to keep my appointments with the doctor?

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.

• Routine tests (e.g. complete blood count, electrolyte levels, liver function, ECG [test used to record the electrical activity of the heart]) may be done before and while you are being treated with this medicine. Your doctor will advise you about how often you need to have these tests.
• Regular monitoring for signs of changes in your balance, coordination, or alertness may also be needed.

Mexiletine may cause tiredness, confusion, or blurred vision. If affected, do not drive or take part in any activity in which you need to be alert or need to see clearly.

Other side effects include any of the following: headache, dizziness, drowsiness, ringing in the ears, nausea, dry mouth, stomach pain, indigestion, constipation, diarrhoea, weakness, difficulty sleeping, rash, acne (also known as pimple), flushing, joint pain, involuntary rhythmic shaking of the hands or legs, and difficulty controlling or coordinating movements.

Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:

• worsening of irregular heartbeat, chest pain, difficulty breathing
• unusual bleeding or bruising
• frequent sore throat, mouth sores, fever, chills or sweating
• rashes, fever, tender or enlarged lymph nodes, swelling of the face
• fits or seizures
• yellowing of the skin or eyes, abdominal pain, dark coloured urine, swelling in the legs and ankles

Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.

Inform your doctor and pharmacist if you are taking any of these medicines:

• other medicines for irregular heartbeat e.g. propafenone, amiodarone, quinidine
• strong painkillers
• antacids (medicines that neutralise stomach acids)
• medicines containing caffeine
• fluvoxamine (medicine to treat depression)
• theophylline (asthma medicine)
• omeprazole (medicine that reduces stomach acid production)
• metoclopramide (medicine for nausea or vomiting)
• ciprofloxacin (certain antibiotic)
• rifampicin (medicine to treat TB, a lung infection known as tuberculosis)
• phenytoin (medicine for epilepsy [fits or seizures])

This list does not include all medicines that may interact with Mexiletine.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements, and medicines that you buy without a prescription.

Avoid alcohol.

Avoid caffeine-containing beverages such as coffee, tea, and certain soft drinks.

Store in a cool, dry place away from the reach of children.

Medicines must not be used past the expiry date.