Mexiletine affects the way that your heart beats.

Mexiletine is used to treat seriously irregular heartbeats.

Mexiletine may also be used for purposes other than those listed in this medication guide.

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.

Use caution when driving, operating machinery, or performing other hazardous activities. Mexiletine may cause dizziness, drowsiness, or blurred vision. If you experience dizziness, drowsiness, or blurred vision, avoid these activities.

Before taking mexiletine, tell your doctor if you have

• any other type of heart disease or heart problem,

• liver disease, or

• seizures or epilepsy.

You may not be able to take mexiletine, or you may require a lower dose or special monitoring during treatment if you have any of the conditions listed above.

Mexiletine is in the FDA pregnancy category C. This means that it is not known whether mexiletine will harm an unborn baby. Do not take this medication without first talking to your doctor if you are pregnant.

Mexiletine passes into breast milk. It is not known whether mexiletine will affect a nursing infant. Do not take this medication without first talking to your doctor if you are breast-feeding a baby.