Mexiletine

Mexiletine changes how your heart beats.

Mexiletine is used to treat serious irregular heartbeats.

Mexiletine may also be used for reasons not mentioned in this medication guide.

Follow all directions on your prescription label. Your doctor may occasionally change your dose to ensure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Mexiletine is usually given at first in a hospital.

Take mexiletine with food or an antacid to reduce stomach upset.

Your heart function may need to be checked using an electrocardiograph or ECG (sometimes called an EKG).

Do not skip doses, change your dosing schedule, or stop taking mexiletine without talking to your doctor. Changing your schedule could make your condition much worse.

Store at room temperature away from moisture, heat, and light.

You should not use mexiletine if you have a serious heart condition such as "AV block" (unless you have a pacemaker).

Mexiletine may cause you to have abnormal liver function tests, especially if you also have congestive heart failure or blood circulation problems.

You should not use mexiletine if you are allergic to it, or if you have:

• a serious heart condition such as "AV block" (unless you have a pacemaker).

To ensure mexiletine is safe for you, tell your doctor if you have:

• liver disease;
• congestive heart failure;
• epilepsy or other seizure disorder;
• a weak immune system (caused by disease or by using certain medicine); or
• if you have recently taken other heart rhythm medicines (disopyramide, lidocaine, quinidine, or others).

FDA pregnancy category C. It is not known whether mexiletine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using mexiletine.

Mexiletine can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Mexiletine may cause you to have abnormal liver function tests, especially if you also have congestive heart failure or blood circulation problems.

Mexiletine may cause serious side effects. Call your doctor at once if you have:

• chest pain;
• a new or a worsening irregular heartbeat pattern; or
• liver problems--nausea, upper stomach pain, itching, feeling tired, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects of mexiletine may include:

• heartburn, upset stomach, nausea, vomiting;
• dizziness, feeling lightheaded;
• tremors, feeling nervous;
• problems with coordination; or
• blurred vision.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Usual Adult Dose for Ventricular Tachycardia:

Initial dose: 200 mg orally every 8 hours when rapid control of arrhythmia is not essential. A minimum of 2-3 days between dose adjustments is recommended. Dose may be adjusted in 50 or 100 mg increments up or down.

Usual Pediatric Dose for Arrhythmias:

1.4 to 5 mg/kg/dose given every 8 hours. Begin with lower initial dosages and titrate to desired effects and serum concentrations.

Try not to miss any doses of this medication. Missing doses could be very dangerous.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include nausea, drowsiness, confusion, feeling lightheaded, seizures, loss of consciousness, and a worsening irregular heartbeat.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Other drugs may interact with mexiletine, including prescription and over-the-counter medicines, vitamins, and herbal products. Inform all your health care providers about all medicines you are currently using and any medicine you begin or stop using.