This medication sometimes produces new irregular heartbeats (arrhythmias). Therefore, it should be used in carefully selected patients. Consult your doctor or pharmacist for more information. Tell your doctor your medical history, especially: blood disorders (e.g., leukopenia, thrombocytopenia), congestive heart failure, low blood pressure, liver disease, history of seizures, any allergies- especially allergies to amide- type anesthetics (e.g., lidocaine, tocainamide) or other drugs. Mexitil should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. Mexitil is excreted into breast milk. Because the possibility of harm to nursing infants exists, consult your doctor before breast-feeding.

Nausea, vomiting, heartburn, dizziness, tremor, changes in vision, nervousness, confusion, headache, fatigue, depression, changes in sleep habits, numbness or tingling especially of the hands or feet, ringing in the ears may occur. If any of these symptoms persist or worsen, notify your doctor. Inform your doctor if you develop: chest pain, rapid heartbeat, general weakness, yellowing of the eyes or skin, fever or sore throat, easy bruising/bleeding. In the unlikely event you have an allergic reaction to this drug, seek immediate medical attention. Symptoms of an allergic reaction include: rash, itching, swelling, severe dizziness, breathing trouble. If you notice other effects not listed above, contact your doctor or pharmacist.

Your doctor may want you to check your pulse rate every day while you take this medication. Learn how to monitor your pulse. Laboratory and/or medical tests (e.g., complete blood counts, liver function tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.