A-Lennon Vitamin B12 Injection

A-LENNON VITAMIN B12 INJECTION is indicated in vitamin B 12 deficiencies manifested by:

• Megaloblastic anaemia and neurological conditions.
• Pernicious anaemia and its neurological complication, subacute combined degeneration of the spinal cord.
• Macrocytic anaemias associated with nutritional deficiencies.
• Intestinal malabsorption, megaloblastosis, diet-related deficiency, post-gastrectomy.

Indications for prophylaxis include strict vegetarianism, post-gastrectomy, and ileal resection and conditions of the small intestine that would predictably cause deficiency.

Administered intramuscularly. In the absence of neurological involvement, A-LENNON VITAMIN B12 INJECTION may be administered in doses of 250 u03bcg to 1 000 u03bcg intramuscularly on alternate days for 1 to 2 weeks, then 250 u03bcg weekly until the blood count returns to normal. Maintenance doses of 1 000 u03bcg are administered monthly. If there is neurological involvement, A-LENNON VITAMIN B12 INJECTION may be given in doses of 1 000 u03bcg on alternate days and continued for as long as improvement occurs. For the prophylaxis of anaemia associated with vitamin B 12 deficiency resulting from gastrectomy or malabsorption syndromes A-LENNON VITAMIN B12 INJECTION may be given in doses of 250 u03bcg to 1 000 u03bcg intramuscularly each month.

A-LENNON VITAMIN B12 INJECTION is contraindicated in:

• Patients with hypersensitivity to vitamin B 12 or to any of the excipients in A-LENNON VITAMIN B12 INJECTION (see COMPOSITION).
• Treatment of toxic amblyopias.
• A-LENNON VITAMIN B12 INJECTION should not be used to treat megaloblastic anaemia of pregnancy.
• A-LENNON VITAMIN B12 INJECTION 10 ml contains benzyl alcohol which must not be given to premature babies or neonates and may cause toxic reactions and anaphylactoid reactions in infants and children up to 3 years old.

• Vitamin B 12 should be given prophylactically only when there is a reasonable indication. Dietary deficiency in the strict vegetarian, the predictable malabsorption of vitamin B 12 in patients who have had gastrectomy, and certain diseases of the small intestine constitute such indications.
• A-LENNON VITAMIN B12 INJECTION should not be given for treatment of deficiency until the diagnosis is fully established.
• Administration of cyanocobalamin doses greater than 10 u03bcg daily may produce haematological response in patients with folate deficiency.
• If megaloblastic anaemia fails to respond to A-LENNON VITAMIN B12 INJECTION, folate metabolism should be investigated.
• Cardiac dysrhythmias secondary to hypokalaemia during initial therapy may occur. Plasma potassium should therefore be monitored during this period.
• Platelet count should be monitored during the first weeks of use in megaloblastic anaemia due to the possible occurrence of reactive thrombocytosis.
• Long-term therapy with A-LENNON VITAMIN B12 INJECTION must be evaluated at intervals of 6 to 12 months in patients who are otherwise well. If there is an additional illness or a condition that may increase the requirement for the vitamin, reassessment should be performed more frequently. It is important to monitor vitamin B 12 concentrations in plasma and to obtain peripheral blood counts at intervals of 3 to 6 months to confirm the adequacy of therapy. Since refractoriness to therapy can develop at any time, evaluation must continue throughout the patientu2019s life.
• Must not be administered intravenously.

• Antibiotics and antimetabolites invalidate vitamin B 12 assays by microbiological techniques.
• Nitrous oxide: prolonged nitrous oxide anaesthesia inactivates vitamin B 12.
• Oral contraceptives: may reduce blood levels of vitamin B 12.
• Folic acid: large doses given continuously may reduce vitamin B 12 in blood.
• Vitamin C: may destroy vitamin B 12.
• Chloramphenicol-treated patients may respond poorly to A-LENNON VITAMIN B12 INJECTION.

The safety of A-LENNON VITAMIN B12 INJECTION in pregnancy and lactation has not been established.

Pregnancy: A-LENNON VITAMIN B12 INJECTION should not be used to treat megaloblastic anaemia of pregnancy.

Lactation: A-LENNON VITAMIN B12 INJECTION is secreted into breast milk.

Since adverse reactions such as dizziness have been reported in patients receiving A-LENNON VITAMIN B12 INJECTION, patients should not drive, use machinery or perform any tasks that require concentration, until they are certain that A-LENNON VITAMIN B12 INJECTION does not adversely affect their ability to do so (see SIDE EFFECTS).

Blood and the lymphatic system disorders

• Less frequent: Reactive thrombocytosis can occur during the first weeks of use in megaloblastic anaemia, signs of polycythaemia vera may be unmasked, hypokalaemia

Immune system disorders

• Less frequent: Hypersensitivity reactions, including skin reactions (e.g. rash, itching) and anaphylaxis

Nervous system disorders

• Less frequent: Dizziness, tremor

Cardiac disorders

• Less frequent: Cardiac dysrhythmias

Gastrointestinal disorders

• Less frequent: Nausea, diarrhoea

Skin and subcutaneous tissue disorders

• Less frequent: Acneiform and bullous eruptions, itching skin

General disorders and administrative site conditions

• Less frequent: Injection site reactions including injection site pain, injection site induration and injection site necrosis. Chills, hot flushing, malaise, fever

Symptoms: See SIDE EFFECTS.

Treatment: Treatment is symptomatic and supportive.