Mexitil affects the way that your heart beats.

Mexitil is used to treat seriously irregular heartbeats.

Mexitil may also be used for purposes not listed in this medication guide.

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

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

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

Mexitil is usually given at first in a hospital.

Take Mexitil with food or an antacid to lessen 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 Mexitil 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 Mexitil if you are allergic to it, or if you have:

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

To make sure Mexitil 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 Mexitil will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using Mexitil.

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

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.

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

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

Mexitil 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, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Common side effects of Mexitil 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 FDA at 1-800-FDA-1088.

Other drugs may interact with mexiletine, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.