KANK-A Mouth Pain Liquid contains benzocaine, a local anesthetic (numbing medication). It works by blocking nerve signals in your body.

KANK-A Mouth Pain Liquid numbs surfaces inside the mouth and is used for treating canker sores and other oral abrasions.

KANK-A should not be used to treat teething pain in infants, and is not approved for use in a child younger than 2 years old.

KANK-A used in the mouth may cause a condition in which the oxygen in your body tissues can become dangerously low. This is a potentially fatal condition called methemoglobinemia (met-HEEM-oh glo-bin-EE-mee-a). Do not use this medicine if you have ever had methemoglobinemia.

GET EMERGENCY MEDICAL HELP IF YOU HAVE SYMPTOMS OF METHEMOGLOBINEMIA: headache, tired feeling, confusion, fast heart rate, and feeling light-headed or short of breath, with a pale, blue, or gray appearance of your skin, lips, or fingernails.

An overdose of KANK-A can cause fatal side effects if too much of the medicine is absorbed through your oral membranes and into your blood. Use the smallest amount needed.

Do not use KANK-A on a child younger than 2 years old.

Before taking this medicine

Do not use KANK-A if you have ever had methemoglobinemia in the past.

An overdose of benzocaine can cause fatal side effects if too much of the medicine is absorbed through your skin and into your blood. This can happen if you apply more than the recommended dose.

Fatal overdoses have occurred when numbing medicines were used without the advice of a medical doctor (such as during a cosmetic procedure like laser hair removal). Be aware that many cosmetic procedures are performed without a medical doctor present.

Ask a doctor or pharmacist if KANK-A is safe to use if you have:

• a personal or family history of methemoglobinemia, or any genetic (inherited) enzyme deficiency;

• asthma, bronchitis, emphysema, or other breathing disorder;

• heart disease; or

• if you smoke.

Ask a doctor before using this medicine if you are pregnant or breast-feeding.

If you apply KANK-A to your chest, avoid areas that may come into contact with the baby's mouth.

Use KANK-A exactly as directed on the label, or as prescribed by your doctor. Read all medication guides or instruction sheets.

Your body may absorb more benzocaine if you use too much, if you apply it over large skin areas, or if you apply heat, bandages, or plastic wrap to treated skin areas. Skin that is cut or irritated may also absorb more topical medication than healthy skin.

Use the smallest amount needed to numb the skin or relieve pain. Do not use large amounts of KANK-A.

Do not use KANK-A to treat large areas inside the mouth.

Call your doctor if your symptoms do not improve or if they get worse within the first 7 days of using KANK-A. Also call your doctor if your symptoms had cleared up but then came back.

If you are treating a sore throat, call your doctor if the pain is severe or lasts longer than 2 days, especially if you also develop a fever, headache, skin rash, swelling, nausea, vomiting, cough, or breathing problems.

Store at room temperature away from moisture and heat. Do not freeze.

Do not use KANK-A if you have ever had methemoglobinemia in the past.

An overdose of benzocaine can cause fatal side effects if too much of the medicine is absorbed through your skin and into your blood. This can happen if you apply more than the recommended dose.

Fatal overdoses have occurred when numbing medicines were used without the advice of a medical doctor (such as during a cosmetic procedure like laser hair removal). Be aware that many cosmetic procedures are performed without a medical doctor present.

Ask a doctor or pharmacist if KANK-A is safe to use if you have:

• a personal or family history of methemoglobinemia, or any genetic (inherited) enzyme deficiency;

• asthma, bronchitis, emphysema, or other breathing disorder;

• heart disease; or

• if you smoke.

Ask a doctor before using this medicine if you are pregnant or breast-feeding.

If you apply KANK-A to your chest, avoid areas that may come into contact with the baby's mouth.

Since KANK-A is used when needed, you may not be on a dosing schedule. Skip any missed dose if it's almost time for your next dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of benzocaine topical applied to the skin can cause life-threatening side effects such as uneven heartbeats, seizure (convulsions), coma, slowed breathing, or respiratory failure (breathing stops).

Avoid eating within 1 hour after using KANK-A on your gums or inside your mouth.

KANK-A is for use just inside the mouth. Avoid getting this medication in your eyes. Avoid swallowing the liquid applying it to your gums or the inside of your mouth.

KANK-A used in the mouth may cause a condition in which the oxygen in your body tissues can become dangerously low. This is a potentially fatal condition called methemoglobinemia (met-HEEM-oh glo-bin-EE-mee-a). This condition may occur after only one use of benzocaine or after several uses.

Signs and symptoms may occur within minutes or up to 2 hours after using KANK-A in the mouth or throat. GET EMERGENCY MEDICAL HELP IF YOU HAVE:

• a headache, tiredness, confusion;

• fast heartbeats;

• feeling light-headed or short of breath; and

• pale, blue, or gray appearance of your skin, lips, or fingernails.

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

Stop using this medicine and call your doctor at once if you have:

• severe burning, stinging, or sensitivity where the medicine is applied;

• swelling, warmth, or redness; or

• oozing, blistering, or any signs of infection.

Common KANK-A side effects may include:

• mild stinging, burning, or itching where the medicine is applied;

• skin tenderness or redness; or

• dry white flakes where the medicine was 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.

Medicine used on the skin is not likely to be affected by other drugs you use. But many drugs can interact with each other. Tell each of your health care providers about all medicines you use, including prescription and over-the-counter medicines, vitamins, and herbal products.