Cyanocobalamin

side effects

CV: heart failure. GI: diarrhea. Derm: itching, swelling of the body. F and E: hypokalemia. Hemat: thrombocytosis. Resp: pulmonary edema. Local: pain at IM site. Misc: hypersensitivity reactions including ANAPHYLAXIS.

trade name

Nascobal

action

Necessary coenzyme for metabolic processes, including fat and carbohydrate metabolism and protein synthesis. Required for cell reproduction and hematopoiesis. Therapeutic Effects: Corrects manifestations of pernicious anemia (megaloblastic indices, GI lesions, and neurologic damage). Corrects vitamin B12 deficiency.

indications

Vitamin B12 deficiency (parenteral products or nasal spray should be used when deficiency is due to malabsorption). Pernicious anemia (parenteral products should be used for initial therapy; nasal or oral products are not indicated until patients have achieved hematologic remission following parenteral therapy and have no signs of CNS involvement). Part of the Schilling test (vitamin B12 absorption test) (diagnostic).

therapeutic classification

antianemic, vitamin

generic name

cyanocobalamin

pharmacologic classification

water soluble vitamins

assessment

● Assess patient for signs of vitamin B12 deficiency (pallor; neuropathy; psychosis; red, inflamed tongue) before and periodically during therapy. ● Lab Test Considerations: Monitor plasma folic acid, vitamin B12, and iron levels, hemoglobin, hematocrit, and reticulocyte count before treatment, 1 mo after the start of therapy, and then every 3- 6 mo. Evaluate serum potassium level in patients receiving vitamin B12 for pernicious anemia for hypokalemia during the first 48 hr of treatment. Serum potassium levels and platelet counts should be monitored routinely during the course of therapy.

client teaching

● Encourage patient to comply with diet recommendations of health care professional. Explain that the best source of vitamins is a well-balanced diet with foods from the four basic food groups. ● Foods high in vitamin B12 include meats, seafood, egg yolk, and fermented cheeses; few vitamins are lost with ordinary cooking. Patients self-medicating with vitamin supplements should be cautioned not to exceed RDA. Effectiveness of megadoses for treatment of various medical conditions is unproved and may cause side effects. ● Inform patients with pernicious anemia of the lifelong need for vitamin B12 replacement. ● Emphasize the importance of follow-up exams to evaluate progress. ● Intranasal: Instruct patient in proper administration technique. Review Patient Information Sheet and demonstrate use of actuator. Unit must be primed with 3 strokes upon using for the first time. Unit must be primed with 1 stroke before each of the remaining doses. Advise patient to clear nose, then place tip approximately 1 inch into nostril and press pump once, firmly and quickly. After dose, remove unit from nose and massage dosed nostril gently for a few seconds. Vial delivers 8 doses. Unit should be stored at room temperature and protected from light.

implementation

● Usually administered in combination with other vitamins; solitary vitamin B12 deficiencies are rare. ● Administration of vitamin B12 by the oral route is useful only for nutritional deficiencies. Patients with small-bowel disease, malabsorption syndrome, or gastric or ileal resections require parenteral administration. ● IM, Subcut: Vials should be protected from light. ● If subcutaneous route used, deep subcutaneous administration is preferred. ● PO: Administer with meals to increase absorption. ● May be mixed with fruit juices. Administer immediately after mixing; ascorbic acid alters stability. ● IV: IV route is not recommended. ● Intranasal: Dose should not be administered within 1 hr of hot foods or liquids (these substances may result in the formation of nasal secretions which may result inpeffectiveness of nasal spray)