Cyanocobalamin

Cyanocobalamin is a manufactured form of vitamin B12 used to treat vitamin B12 deficiency. This may occur in pernicious anemia, following surgical removal of the stomach, with fish tapeworm, or due to bowel cancer. It is less preferred than hydroxocobalamin. It is used by mouth, by injection into a muscle, or as a nasal spray. Cyanocobalamin is a manufactured form of vitamin B12 used to treat vitamin B12 deficiency. This may occur in pernicious anemia, following surgical removal of the stomach, with fish tapeworm, or due to bowel cancer. It is less preferred than hydroxocobalamin. It is used by mouth, by injection into a muscle, or as a nasal spray. Cyanocobalamin is generally well tolerated. Minor side effect may include diarrhea and itchiness. Serious side effects may include anaphylaxis, low blood potassium, and heart failure. Use is not recommended in those who are allergic to cobalt or have Leber's disease. Vitamin B12 is an essential nutrient meaning that it cannot be made by the body but is required for life. Cyanocobalamin was first manufactured in the 1940s. It is available as a generic medication and over the counter. In the United Kingdom it costs the NHS about 2.90 £ per injection as of 2019. In the United States the wholesale cost of this amount is about US$0.77. In 2016 it was the 137th most prescribed medication in the United States with more than 4 million prescriptions. Cyanocobalamin is usually prescribed after surgical removal of part or all of the stomach or intestine to ensure adequate serum levels of vitamin B12. It is also used to treat pernicious anemia, vitamin B12 deficiency (due to low intake from food), thyrotoxicosis, hemorrhage, malignancy, liver disease and kidney disease. Cyanocobalamin injections are often prescribed to gastric bypass patients who have had part of their small intestine bypassed, making it difficult for B12 to be acquired via food or vitamins. Cyanocobamide is also used to perform the Schilling test to check ability to absorb vitamin B12. Possible side effects of cyanocobalamin injection include allergic reactions such as hives, difficult breathing; redness of the face; swelling of the arms, hands, feet, ankles or lower legs; extreme thirst; and diarrhoea. Less-serious side effects may include headache, dizziness, leg pain, itching, or rash. Treatment of megaloblastic anemia with concurrent vitamin B12 deficiency using B12 vitamers (including cyanocobalamin), creates the possibility of hypokalemia due to increased erythropoiesis (red blood cell production) and consequent cellular uptake of potassium upon anemia resolution. When treated with vitamin B12, patients with Leber's disease may suffer serious optic atrophy, possibly leading to blindness. Vitamin B12 the 'generic descriptor' name for any vitamers of vitamin B12. Animals, including humans, can convert cyanocobalamin to any one of the active vitamin B12 compounds. Cyanocobalamin is one of the most widely manufactured vitamers in the vitamin B12 family (the family of chemicals that function as B12 when put into the body), because cyanocobalamin is the most air-stable of the B12 forms. It is the easiest to crystallize and therefore easiest to purify after it is produced by bacterial fermentation, or synthesized in vitro. It can be obtained as dark red crystals or as an amorphous red powder. Cyanocobalamin is hygroscopic in the anhydrous form, and sparingly soluble in water (1:80). It is stable to autoclaving for short periods at 121 °C (250 °F). The vitamin B12 coenzymes are unstable in light. After consumption the cyanide ligand is replaced by other groups (adenosyl, methyl), which are the biologically active forms. The cyanide is converted to thiocyanate and excreted by the kidney.. In the cobalamins, cobalt normally exists in the trivalent state, Co(III). However, under reducing conditions, the cobalt center is reduced to Co(II) or even Co(I), which are usually denoted as B12rand B12s, for reduced and super reduced, respectively.