Nascobal (for use in the nose) is used to treat vitamin B12 deficiency in people with pernicious anemia and other conditions.

Nascobal is usually given after treatment with an injection form of Nascobal.

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

You should not use Nascobal if you are allergic to cobalt, or if you have Leber's disease.

Nascobal is usually given once per week. Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

You may need blood tests every 3 to 6 months, and your doctor may change your dose based on the results.

Your dose needs may change if you become pregnant, if you breast-feed, or if you eat a vegetarian diet. Tell your doctor about any changes in your diet or medical condition.

Tell your doctor if you have sinus congestion. Nascobal may not work as well if you have a stuffy nose.

For pernicious anemia, you may have to use Nascobal for the rest of your life. Do not stop using the medicine unless your doctor tells you to. Untreated vitamin B12 deficiency can lead to anemia or irreversible nerve damage.

Pernicious anemia is also treated with folic acid to help maintain red blood cells. Folic acid alone will not treat Vitamin B12 deficiency or prevent possible damage to the spinal cord. Use all medications as directed.

Store in an upright position at room temperature. Protect from light and do not freeze.

You should not use this medicine if you are allergic to Nascobal or cobalt, or if you have Leber's disease (an inherited form of vision loss). This medicine can lead to optic nerve damage (and possibly blindness) in people with Leber's disease.

Tell your doctor if you have ever had:

• eye problems or Leber's disease (in you or a family member); or

• an iron or folic acid deficiency.

Tell your doctor if you are pregnant or breast-feeding. Your dose needs may be different during pregnancy or while you are nursing a baby.

Nascobal is not approved for use by anyone younger than 18 years old.

Use the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not use two doses at one time.

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

Do not drink hot liquid or eat hot food within 1 hour before or 1 hour after you use Nascobal.

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

Call your doctor at once if you have :

• easy bruising, unusual bleeding, purple or red spots under your skin; or

• low potassium level--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling.

Common side effects of Nascobal may include:

• runny nose;

• cold or flu symptoms such as stuffy nose, sore throat, sinus pain;

• headache;

• tingling in your hands or feet;

• weakness;

• nausea; or

• swelling in your tongue.

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.

Other drugs may affect Nascobal, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.