Find & Manage Your Patient Assistance Programs
Estimated patient savings $600,000,000.00

Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.





This medication is used to treat irregular heartbeats (arrhythmias).



This drug may also be used for resistant seizure treatment.

How To Use

This medication is generally given by vein (IV). It may also be given in a large muscle (IM - in the shoulder usually) for one or two doses if necessary. Generally 50-100mg is given first IV, then repeated if necessary. This dosing is followed by continuous IV therapy (1-4 mg per minute typically). Doses may need to be reduced in people with heart failure or liver problems.

Side Effects

Pain at the site of injection might occur. If this persists or worsens, notify your doctor. Unlikely but report promptly: drowsiness, dizziness, confusion, shakiness, mental changes, ringing in the ears, visual changes, nausea, tingling or numbness, slurred speech, muscle twitching, unusually slow heartbeat, seizures. Notify your doctor immediately if an allergic reaction occurs. Symptoms include: difficulty breathing, skin rash, itching, swelling. If you notice other effects not listed above, contact your doctor or pharmacist.


Before using this drug, tell your doctor your medical history, including: allergies (especially drug allergies), heart problems, liver disease, severe lung problems. This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. This drug is excreted into breast milk. Consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of all nonprescription and prescription medication you may use, especially of: cimetidine, other drugs used for irregular heartbeats (arrhythmias) such as phenytoin, procainamide, quinidine, propranolol. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include seizures, shortness of breath, and slow heartbeat.


This drug may interfere with laboratory tests (CK and CPK) when given by injection into a muscle (IM). EKG and other heart monitoring will occur during therapy.

Missed Dose

If a dose is missed or IV is interrupted, notify your doctor or pharmacist promptly.


Store at controlled room temperature away from light and moisture.