Laboratory Monitoring Hematocrit, reticulocyte count, vitamin B12, folate, and iron levels should be obtained prior to treatment. All hematologic parameters, including vitamin B12 concentrations, should be normal before initiating treatment with CaloMist Nasal Spray. Periodic monitoring of serum vitamin B12 concentrations must be obtained to confirm adequacy of therapy. Vitamin B12 concentrations and complete blood counts should be monitored one month after starting CaloMist Nasal Spray and then at 3 to 6 month intervals thereafter. Patients with borderline-low vitamin B12 concentrations (<300 ng/L) should also undergo measurement of methylmalonic acid and homocysteine concentrations, which are more sensitive measures of vitamin B12 deficiency in this setting. Patients with declining or abnormally low vitamin B12 concentrations despite maximal doses of CaloMist Nasal Spray should be switched back to intramuscular vitamin B12 injections. Vitamin B12 deficiency that is inadequately treated for longer than three months may produce irreversible neurological damage. Use in Patients With Nasal Pathology CaloMist Nasal Spray has not been evaluated in patients with nasal pathology. Treatment with CaloMist Nasal Spray should be deferred until nasal symptoms have subsided. Patients with chronic nasal symptoms or significant nasal pathology are not ideal candidates for intranasal vitamin B12 therapy. If CaloMist Nasal Spray therapy is attempted in these patients, vitamin B12 concentrations should be monitored more frequently than in patients without nasal pathology because of the potential for erratic or blunted absorption. Use in Patients with Leber's Disease Patients with early Leber's disease (hereditary optic nerve atrophy) who were treated with cyanocobalamin suffered severe and swift optic atrophy. Cyanocobalamin should not be used in these patients. Anaphylaxis and Angioedema Anaphylactic shock, death, and angioedema were not reported in the CaloMist Nasal Spray clinical trial but have been reported with parenteral vitamin B12 administration. Megaloblastic Anemia Megaloblastic anemia has many causes, including vitamin B12 deficiency and folate deficiency. Folic acid may result in a hematological response in patients with vitamin B12 deficiency, but will not prevent irreversible neurological manifestations. Vitamin B12 is not an appropriate treatment for folate deficiency. Hypokalemia, thrombocytosis, and sudden death may occur when severe megaloblastic anemia is treated intensely with vitamin B12. Serum potassium and the platelet count should be carefully monitored in this setting. Blunted Response to Vitamin B12 Therapy Infections, uremia, concurrent iron or folic acid deficiency, and drugs with bone marrow suppressant properties (e.g., chloramphenicol) may blunt the therapeutic response to vitamin B12 products, including CaloMist Nasal Spray. Nonclinical Toxicology Carcinogenesis, Mutagenesis, Impairment of Fertility There are no long-term studies in animals that have evaluated the carcinogenic potential of any of the vitamin B12 products, including CaloMist Nasal Spray. There is no evidence from long-term use in patients with pernicious anemia that vitamin B12 is carcinogenic. Pernicious anemia is associated with an increased incidence of carcinoma of the stomach, but this malignancy has been attributed to the underlying pathology of pernicious anemia and not to treatment with vitamin B12. Use In Specific Populations Pregnancy Pregnancy Category C Animal reproduction studies have not been conducted with CaloMist Nasal Spray. Although vitamin B12 is an essential vitamin and requirements are increased during pregnancy, it is not known whether CaloMist Nasal Spray can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. CaloMist Nasal Spray should be given to a pregnant woman only if clearly needed. Adequate and well-controlled studies have not been conducted in pregnant women. Nursing Mothers Although vitamin B12 is an essential vitamin and requirements are increased during lactation, it is not known whether CaloMist Nasal Spray can cause harm to an infant when administered to a nursing woman. Vitamin B12 appears in the milk of nursing mothers in concentrations that approximate the mother's vitamin B12 blood level. Caution should be exercised when CaloMist Nasal Spray is administered to a nursing woman. Pediatric Use Because CaloMist Nasal Spray has not been studied in children, safety and effectiveness have not been established in pediatric patients. Geriatric Use Clinical studies of CaloMist Nasal Spray did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Renal/Hepatic Impairment Patients with vitamin B12 deficiency and concurrent renal or hepatic disease may require increased doses or more frequent administration of vitamin B12 therapy. Last reviewed on RxList: 8/16/2007
This monograph has been modified to include the generic and brand name in many instances.