2.1 Testing and Other Considerations Prior to Dosing

Prior to treatment, obtain hematocrit, reticulocyte count, vitamin B12, folate, and iron levels [see Dosage and Administration (2.4)]. Consider the potential for concomitant drugs to interfere with vitamin B12 and folate diagnostic blood assays [see Drug Interactions (7)].

In patients with suspected cobalamin hypersensitivity, consider administering an intradermal test dose of parenteral vitamin B12 prior to use of NASCOBAL [see Warnings and Precautions (5.2)].

Recommended Dosage

The recommended initial dose of NASCOBAL is one spray (500 mcg) administered in ONE nostril once weekly. Administer NASCOBAL at least one hour before or one hour after ingestion of hot foods or liquids since hot foods may cause nasal secretions and a resulting loss of medication. Defer use of NASCOBAL in patients with nasal congestion, allergic rhinitis, or upper respiratory infections until after symptoms have subsided.

Monitoring, Dosage Modifications, and Treatment Duration

Monitoring for Response and Safety

Monitor serum B12 levels periodically during therapy to establish adequacy of therapy. Obtain a serum B12 level and peripheral blood count one month after treatment initiation, then subsequently at intervals of 3 to 6 months [see Warnings and Precautions (5.3)].

Dosage Modifications

If serum levels of B12 decline after one month of treatment with NASCOBAL, consider increasing the dose. Assess serum B12 level one month after each dose adjustment. If serum B12 levels are persistently low, consider alternative therapy (e.g., intramuscular or subcutaneous vitamin B12 therapy).

Treatment Duration

In patients whose underlying cause of vitamin B12 deficiency has been corrected and are deemed no longer at risk for vitamin B12 deficiency, discontinue NASCOBAL. The safety and effectiveness of continued long-term use in these individuals has not been established.

In patients with pernicious anemia, continue appropriate vitamin B12 treatment indefinitely.

2.4 Administration of NASCOBAL with Other Therapy

NASCOBAL should be administered with other therapy(ies) in:

• Patients with concurrent folate and vitamin B12 deficiency:Administer folic acid in addition to NASCOBAL
• Patients with concurrent iron and vitamin B12 deficiency:Administer iron in addition to NASCOBAL
• Patients with correctible causes of vitamin B12 deficiency:Consider measures to treat the underlying condition associated with vitamin B12 deficiency in addition to treatment with NASCOBAL