Anemia

• Anemia


  Hemoglobin concentration below normal resulting from a decreased number of circulating red blood cells or an abnormally low total hemoglobin concentration

  
• General signs and symptoms of anemia

  • Fatigue
  • Rapid heart beat
  • Shortness of breath
  • Pale skin
  • Dizziness
  • Insomnia
  • Headache
  • Cold hands or feet
• Drugs can cause toxic effects on blood cells, which may cause anemia
• Nutritional anemia


  Caused by dietary deficiencies such as iron, folic acid, and vitamin B12 that are necessary for normal erythropoiesis

  
• Iron


  Stored in the intestinal mucosal cells, liver, spleen, and bone marrow as ferritin until needed by the body
• Transferrin


  A transport protein that delivers iron to the marrow for hemoglobin production
• Iron deficiency can result from blood loss, insufficient intake during periods of accelerated need
• Iron deficiency


  Hypochromic microcytic anemia
• Signs and symptoms of iron deficiency anemia

  • Pica
  • Koilonychias
  • Soreness and cracking at the corners of the mouth
• Iron supplementation


  Corrects the iron deficiency
• CDC recommends 150 to 180 mg/day of oral elemental iron administered in divided doses two to three times daily for patients with iron deficiency anemia

  
• Iron absorption


  1. Absorbed after oral administration

  2. Kept in ferrous form by acidic conditions

  3. Absorbed in the duodenum
• The amount of iron absorbed depends on the current body stores of iron
• Oral iron preparations


  • Ferrous sulfate
  • Ferrous fumarate
  • Ferrous gluconate

  
• Ferrous sulfate is the most commonly used form of iron due to its high content of elemental iron and relatively low cost
• Parenteral formulations of iron

  • Iron dextran
  • Iron sucrose
• Parenteral administration treats iron deficiency rapidly while oral administration may take several weeks
• Folic acid


  Primary use is in treating deficiency states that arise from inadequate levels of folate
• Causes of folate deficiency

  • Increased demand
  • Poor absorption
  • Alcoholism
  • Treatment with drugs that are dihydrofolate reductase inhibitors
• Megaloblastic anemia


  Primary result of folic acid deficiency
• Megaloblastic anemia presents with large sized red blood cells caused by diminished synthesis of purines and pyrimidines

  
• Folic acid is well absorbed in the jejunum unless pathology is present
• Vitamin B12 deficiency


  Can result from low dietary levels or poor absorption due to failure of gastric parietal cells to produce intrinsic factor

  
• Pernicious anemia is caused by intrinsic factor deficiency
• Vitamin B12 supplementation is required for patients with bariatric surgery

  
• Signs and symptoms of vitamin B12 deficiency


  • General signs and symptoms of anemia
  • Tingling in the hands and feet
  • Difficulty walking
  • Dementia
  • Hallucinations
  • Paranoia
  • Schizophrenia

  
• Vitamin B12 administration


  1. Orally for dietary deficiencies

  2. Intramuscularly or deep subcutaneously for pernicious anemia

  
• Folic acid administration alone can mask vitamin B12 deficiency

  
• Megaloblastic anemia should not be treated with folic acid alone but with a combination of folate and vitamin B12

  
• Erythropoietin


  A glycoprotein that stimulates stem cells to differentiate into proerythroblasts and promotes the release of reticulocytes from the marrow
• EPO regulates red blood cell proliferation and differentiation in bone marrow
• Human erythropoietin epoetin alfa is effective in the treatment of anemia caused by end stage renal disease and other conditions

  
• Darbepoetin


  A long acting version of erythropoietin with a half-life three times that of epoetin alfa
• Darbepoetin has no value in acute treatment of anemia due to its delayed onset of action
• Supplementation with iron may be required to ensure an adequate response to erythropoietin
• The protein is usually administered intravenously in renal dialysis patients but the subcutaneous route is preferred for other indications
• Side effects of erythropoietin and darbepoetin

  • Elevation in blood pressure
  • Arthralgia
• Neutropenia is an abnormally low concentration of neutrophils in the blood
• Neutrophils serve as the primary defense against infections
• Causes of neutropenia


  • Chemotherapy
  • Cancer
  • Blood and bone marrow disorders
  • Autoimmune diseases
  • Deficiencies in vitamins or minerals