Cyanocobalamin crystalline
Cyanocobalamin crystalline
Cyanocobalamin
(sye-
an-oh-koh-
BAL-ah-min)
Pregnancy Category: C
Crystamine
Crysti 1000
Cyanoject
Cyomin
Rubesol-1000
(OTC)
(Rx)
Classification:
Vitamin
B12
Action/Kinetics:
Required for hematopoiesis, cell reproduction, nucleoprotein and myelin synthesis. Plasma vitamin B
12 levels: 150-750 pg/mL. Rapidly absorbed following IM or SC administration. Following absorption, vitamin B
12 is carried by plasma proteins to the liver where it is stored until required for various metabolic functions.
t
1/2: 6 days (400 days in the liver).
Time to peak levels, after PO: 8-12 hr.
Uses:
Cyanocobalamin Gel/Tablets: Nutritional vitamin B
12 deficiency; not to be used for treatment of pernicious anemia.
Cyanocobalamin Parenteral: Vitamin B
12 deficiency due to malabsorption syndrome as seen in pernicious anemia. GI pathology, dysfunction, or surgery. Fish tapeworm infestation, maligancy of pancreas or bowel, gluten enteropathy, small bowel overgrowth of bacteria, sprue, accompanying folic acid deficiency, or total or partial gastrectomy.
Contraindications:
Hypersensitivity to cobalt, Leber's disease.
Special Concerns:
Use with caution in clients with gout.
Side Effects:
Following parenteral use.
Allergic: Urticaria, itching, transitory exanthema,
anaphylaxis, shock, death.
CV:
Peripheral vascular thrombosis CHF,
pulmonary edema.
Other: Polycythemia vera, optic nerve atrophy in clients with hereditary optic nerve atrophy, diarrhea, hypokalemia, body feels swollen.
Following intranasal use.
GI: Glossitis, N&V.
Miscellaneous: Asthenia, headache, infection (sore throat, common cold), paresthesia, rhinitis.
NOTE: Benzyl alcohol, which is present in certain products, may cause
a fatal ``gasping syndrome'' in premature infants.
Laboratory Test Alterations:
Antibiotics, methotrexate, or pyrimethamine invalidate folic acid and vitamin B
12 diagnostic blood assays.
Drug Interactions:
-
Alcohol /
Vitamin B
12 absorption
-
Aminosalicylic acid /
Vitamin B
12 effect. Also, abnormal Schilling test and symptoms of vitamin B
12 deficiency
-
Chloramphenicol /
Response to vitamin B
12 in pernicious anemia
-
Cholestyramine /
Vitamin B
12 absorption
-
Cimetidine /
Digestion and release of vitamin B
12
-
Colchicine /
Vitamin B
12 absorption
-
Neomycin /
Vitamin B
12 absorption
-
PAS /
Vitamin B
12 absorption
-
Potassium, timed-release /
Vitamin B
12 absorption
How Supplied:
Cyanocobalamin:
Gel: 400 mcg/unit, 500 mcg/0.1 mL;
Tablet: 25 mcg, 50 mcg, 100 mcg, 250 mcg;
Cyanocobalamin crystalline:
Injection:100 mcg/mL, 1,000 mcg/mL;
Tablets; 500 mcg, 1000 mcg
Dosage
Cyanocobalamin
?Tablets
Nutritional supplement.
Adults: 1 mcg/day (up to 25 mcg for increased requirements). The RDA is 2 mcg/day.
Pediatric, up to 1 year: 0.3 mcg/day;
over 1 year: 1 mcg/day.
Nutritional deficiency.
25-250 mcg/day.
?Nasal gel
Nutritional deficiency.
500 mcg/0.1 mL weekly given intranasally.
Cyanocobalamin crystalline
?IM, Deep SC
Addisonian pernicious anemia.
Adults: 100 mcg/day for 6-7 days;
then, if improvement is noted along with a reticulocyte response, give 100 mcg every other day for seven doses and then 100 mcg q 3-4 days for 2-3 weeks.
Maintenance, IM: 100 mcg once a month for life. Give folic acid if necessary.
Vitamin B
12 deficiency.
Adults: 30 mcg daily for 5-10 days;
then 100-200 mcg/month. Doses up to 1,000 mcg have been recommended.
Pediatric, for hematologic signs: 10-50 mcg/day for 5-10 days followed by 100-250 mcg/dose q 2-4 weeks.
Pediatric, for neurologic signs: 100 mcg/day for 10-15 days;
then 1-2 times/week for several months (can possibly be tapered to 250-1,000 mcg/month by 1 year).
Diagnosis of vitamin B
12 deficiency.
Adults: 1 mcg/day IM for 10 days plus low dietary folic acid and vitamin B
12. Loading dose for the Schilling test is 1,000 mcg given IM.
