Lidocaine is a local anesthetic (numbing medication) that is used to numb an area of your body to help reduce pain or discomfort caused by invasive medical procedures such as surgery, needle punctures, or insertion of a catheter or breathing tube.

Lidocaine injection is sometimes used to treat irregular heart rhythms that may signal a possible heart attack.

Lidocaine injection is also given in an epidural (spinal block) to reduce the discomfort of contractions during labor.

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

You should not receive lidocaine injection if you have severe heart block, or a heart rhythm disorder called Stokes-Adams syndrome or Wolff-Parkinson-White Syndrome.

A healthcare provider will give you this injection.

When used to treat heart rhythm problems, lidocaine is given as an infusion into a vein.

When used as a local anesthetic, lidocaine is injected through the skin directly into the body area to be numbed.

Your breathing, blood pressure, oxygen levels, and other vital signs will be watched closely while you are receiving lidocaine injection in a hospital setting.

If you are being treated for irregular heart rhythm, your heart rate will be constantly monitored using an electrocardiograph or ECG (sometimes called an EKG). This will help your doctor determine how long to treat you with lidocaine injection.

You should not receive this medicine if you are allergic to lidocaine injection or any other type of numbing medicine, or if you have:

• severe heart block;

• a heart rhythm disorder called Stokes-Adams syndrome (sudden slow heart beats that can cause you to faint); or

• a heart rhythm disorder called Wolff-Parkinson-White Syndrome (sudden fast heartbeats that can cause you to faint or become easily tired).

Tell your doctor if you have ever had:

• an allergy to corn products;

• liver disease;

• kidney disease;

• heart disease (unless you are being treated with lidocaine injection for a heart condition);

• coronary artery disease, circulation problems; or

• malignant hyperthermia.

Tell your doctor if you are pregnant or breastfeeding.

Since lidocaine injection is used only when needed in a clinical setting, you are not likely to miss a dose.

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

Lidocaine injection can cause side effects that may impair your thinking or reactions. Unless absolutely necessary, do not drive after receiving lidocaine injection.

Avoid eating or chewing within 1 hour after lidocaine injection is used to numb your mouth or throat. You may have trouble swallowing which could lead to choking. You may also accidentally bite the inside of your mouth if you are still numb an hour after treatment with lidocaine injection.

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

Tell your caregiver right away if you have:

• twitching, tremors, seizure (convulsions);

• a light-headed feeling, like you might pass out;

• slow heart rate, weak pulse, weak or shallow breathing;

• sudden feeling of heat, cold, or numbness;

• muscle stiffness and pain;

• weak or shallow breathing;

• blue appearance of the skin; or

• severe anxiety, unusual fear or uneasy feeling.

Common side effects of lidocaine injection may include:

• drowsiness, dizziness;

• nausea, vomiting;

• feeling hot or cold;

• confusion, ringing in your ears, blurred vision, double vision; or

• numbness in places where the medicine is accidentally applied.

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.

Tell your doctor about all your other medicines, especially:

• cimetidine, fluvoxamine, nefazodone, St John's wort;

• antibiotic or antifungal medicine;

• antiviral medicine to treat hepatitis or HIV/AIDS;

• heart or blood pressure medicine--amiodarone, digoxin, nicardipine, procainamide, propranolol;

• seizure medicine--carbamazepine, phenytoin; or

• tuberculosis medicine--isoniazid, rifampin.

This list is not complete. Other drugs may affect lidocaine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.