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What is the primary cause of iron deficiency anemia?
What is the primary cause of iron deficiency anemia?
Which of the following enhances iron absorption?
Which of the following enhances iron absorption?
What is the initial form of iron that is absorbed in the small intestine?
What is the initial form of iron that is absorbed in the small intestine?
Which type of anemia is characterized by the body's failure to produce blood cells?
Which type of anemia is characterized by the body's failure to produce blood cells?
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Which of the following statements about the iron fraction is correct?
Which of the following statements about the iron fraction is correct?
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What condition is often considered an indication for iron therapy due to decreased intake?
What condition is often considered an indication for iron therapy due to decreased intake?
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What is the consequence of iron being oxidized in mucosal cells?
What is the consequence of iron being oxidized in mucosal cells?
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In which condition is parental iron administration primarily indicated?
In which condition is parental iron administration primarily indicated?
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Which of the following is a common cause of acute iron toxicity in children?
Which of the following is a common cause of acute iron toxicity in children?
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What is a potential side effect of intravenous iron dextran?
What is a potential side effect of intravenous iron dextran?
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What is the primary role of vitamin B12 in the body?
What is the primary role of vitamin B12 in the body?
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Which medication is used as an iron chelator in cases of iron toxicity?
Which medication is used as an iron chelator in cases of iron toxicity?
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Which of the following compounds is needed for the absorption of vitamin B12?
Which of the following compounds is needed for the absorption of vitamin B12?
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What can excessive iron deposition in the organs lead to?
What can excessive iron deposition in the organs lead to?
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Which vitamin deficiency is associated with megaloblastic anemia?
Which vitamin deficiency is associated with megaloblastic anemia?
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What can be a complication of chronic iron toxicity due to excessive blood transfusions?
What can be a complication of chronic iron toxicity due to excessive blood transfusions?
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Which of the following is a cause of vitamin B12 deficiency?
Which of the following is a cause of vitamin B12 deficiency?
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Which manifestation is specifically associated with vitamin B12 deficiency?
Which manifestation is specifically associated with vitamin B12 deficiency?
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What is the recommended treatment for pernicious anemia?
What is the recommended treatment for pernicious anemia?
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What is a common cause of folic acid deficiency?
What is a common cause of folic acid deficiency?
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Which vitamin is essential for DNA synthesis and erythropoiesis?
Which vitamin is essential for DNA synthesis and erythropoiesis?
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What should be administered before giving folic acid in a patient with deficiencies?
What should be administered before giving folic acid in a patient with deficiencies?
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Which of the following conditions is treated with hydroxocobalamine?
Which of the following conditions is treated with hydroxocobalamine?
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What is a common result of severity in vitamin B12 deficiency?
What is a common result of severity in vitamin B12 deficiency?
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Study Notes
Anemia
- Defined as the deficiency of circulating red blood cells or low total hemoglobin content per unit volume of blood.
Classification of Anemia
-
Deficiency Anemia:
- Iron deficiency anemia
- Hypochromic-microcytic
- Vitamin B12 and folic acid deficiency anemia
- Macrocytic anemia
- Iron deficiency anemia
-
Aplastic Anemia:
- The body fails to produce blood cells. This can be primary (idiopathic) or secondary to drugs like anticancers and antithyroids.
-
Hemolytic Anemia:
- Excessive blood cell destruction due to congenital anomalies of red blood cells, like congenital spherocytosis, or hemolytic disease of newborns.
Iron Deficiency Anemia
-
Actions of Iron:
- Essential metallic component of heme, responsible for oxygen transport in the blood.
- Present in iron-containing enzymes in mitochondria.
-
Pharmacokinetics:
-
Absorption:
- Approximately 10% of ingested iron is absorbed.
- Mostly absorbed from the small intestine (duodenum) in the ferrous state.
-
Factors that increase absorption:
- Gastric Acidity
- Ascorbic acid
-
Factors that decrease absorption:
- Antacids
- Tannic Acid
- Malabsorption Syndrome.
-
Transport and Storage:
- Oxidized in mucosal cells to ferric form.
- Travels through the blood (bound to transferrin), and ends in bone marrow where it's involved in red cell formation.
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Elimination:
- Small amounts of iron are lost through sweat, saliva (0.5 mg per day).
-
Absorption:
Causes of Iron Deficiency Anemia
- Decrease Intake: Poor diet or malabsorption.
- Increase Demand: Pregnancy.
- Excess Blood Loss
Iron Preparations
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Oral Preparation:
- Given after meals to avoid GIT irritation for 3-6 months.
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Parental Iron (Inability to tolerate or absorb oral iron, severe anemia or severe blood loss):
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Forms:
- Iron dextran (IM-IV)
- Iron dextrin (IV)
- Iron sorbitol citric acid (IM)
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Forms:
- Ferrous sulfate
- Ferrous gluconate
- Ferrous fumarate
-
Forms:
-
Side Effects:
-
Oral Preparation:
- GIT upset (minimal with iron gluconate)
- Constipation or diarrhea
- Black stools
- Black discoloration of teeth
-
Parental Iron:
- Anaphylaxis
- Local pain and tissue staining with IM injection
- Headache, bronchospasm, tachycardia
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Oral Preparation:
Iron Toxicity
-
Acute Toxicity:
- Common in children due to accidental ingestion of iron tablets.
-
Manifestations:
- Abdominal pain, vomiting, diarrhea, bloody stool
- Shock, dyspnea
- Metabolic acidosis, coma, and death.
- **Chronic Toxicity **
- Cause: Excess iron absorption, hemochromatosis, excess blood transfusions
- Manifestations: Excess iron deposition in the liver, pancreas, skin
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Treatment:
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Acute: Gastric lavage with phosphate or carbonate solution to form insoluble complex.
- Desferrioxamine (Desferal): Iron-chelating agent (IM or IV infusion)
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Acute: Gastric lavage with phosphate or carbonate solution to form insoluble complex.
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Chronic:
- Blood donation (one unit per week) until excess iron is removed (phlebotomy)
- Desferrioxamine when phlebotomy cannot be performed
Megaloblastic Anemia
-
Vitamin B12:
-
Actions:
- Essential for hemopoiesis (blood cell formation)
- Important for DNA synthesis
- Myelination of nerve fibers in the central nervous system.
-
Pharmacokinetics:
-
Absorption:
- Depends on the presence of intrinsic factors.
- Vitamin B12 is absorbed from the ileum in combination with intrinsic factor.
-
Drugs that interfere with absorption:
- Colchicine
- Antiepileptic drugs
- Metformin
-
Distribution and Storage:
- Bound to alpha (transcobalamine I) and beta globulin (transcobalamine II)
- Stored in the liver and kidney.
- Excretion: Bile and urine.
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Absorption:
-
Actions:
-
Causes of Vitamin B12 deficiency:
- Decrease intake
- Increase demands (pregnancy)
- Decrease intrinsic factor (autoimmune atrophic gastritis, gastrectomy)
- Terminal ileum disease
-
Manifestation of Vitamin B12 deficiency:
- Blood: Megaloblastic anemia (macrocytic anemia)
- GIT: Glossitis and diarrhea
-
CNS:
- Subacute combined degeneration of the spinal cord
- Posterior column degeneration leading to deep sensory loss.
- Pyramidal tract degeneration leading to paraplegia.
- Peripheral neuritis
- Subacute combined degeneration of the spinal cord
Vitamin B12 Preparations
- Cyanocobalamine: IM
- Hydroxycobalamine: IM
Uses of Vitamin B12
- Megaloblastic and pernicious anemia
- Peripheral neuropathy
- Cyanide poisoning (Hydroxycobalamine)
Pernicious Anemia
- Occurs due to atrophy of the gastric mucosa, making it unable to secrete intrinsic factor, which is necessary for the absorption of vitamin B12.
- Treated with cyanocobalamine (1000 ug IM daily for 2 weeks, then once a week for the patient's life.
Folic Acid
-
Actions:
- Synthesis of DNA (essential for purine ring synthesis)
- Essential, with vitamin B12, for erythropoiesis
-
Causes of Folic Acid Deficiency:
- Decrease intake
- Decrease absorption
- Increase demands (pregnancy, children)
- Drugs: methotrexate
-
Manifestations of Folic Acid Deficiency:
- Megaloblastic anemia
-
Uses of Folic Acid:
- Megaloblastic anemia
- There is deficiency of both vitamin B12 and folic acid.
- If both deficiencies are present, both agents should be given, but vitamin B12 must be used before folic acid.
- Malabsorption syndrome
- Pregnancy
- To prevent toxicity of antifolate drugs:
- Methotrexate
- Oral contraceptives (decrease folic acid absorption)
- Phenytoin (increases folic acid metabolism)
- Megaloblastic anemia
Aplastic Anemia
-
Management:
- Stop the responsible drug.
- Give fresh blood transfusion.
- Penicillin for infection.
- Corticosteroids to inhibit immune reaction.
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Description
Explore the various classifications of anemia, including deficiency anemia, aplastic anemia, and hemolytic anemia. Understand the role of iron in the body and its significance in oxygen transport. This quiz will help you grasp the intricacies of anemia and its impact on health.
