What is the therapeutic regimen for anemia?

Therapeutic Regimen for Anemia

The treatment of anemia should include iron supplementation with ferrous sulfate 200 mg three times daily for at least three months after correction of anemia to replenish iron stores, with the goal of normalizing hemoglobin levels and red cell indices. 1

Diagnosis and Evaluation

• Anemia is diagnosed when hemoglobin concentration is <13.0 g/dL in males and <12.0 g/dL in females 1
• For children, anemia is diagnosed when hemoglobin is <11.0 g/dL (ages 0.5-5 years), <11.5 g/dL (ages 5-12 years), and <12.0 g/dL (ages 12-15 years) 1
• Initial evaluation should include complete blood count, iron studies (serum ferritin, transferrin saturation), and assessment for underlying causes 1, 2
• Iron deficiency is diagnosed by low serum ferritin (<30 ng/mL) in individuals without inflammatory conditions or by transferrin saturation less than 20% 2

Treatment Algorithm

Iron Deficiency Anemia

1. Oral Iron Therapy (First-line):

   • Ferrous sulfate 200 mg three times daily (providing 65 mg elemental iron per tablet) 1, 3
   • Alternative iron compounds include ferrous gluconate and ferrous fumarate, which are equally effective 1
   • Continue treatment for three months after correction of anemia to replenish iron stores 1
   • Monitor hemoglobin concentration and red cell indices at three-month intervals for one year, then after a further year 1

2. Strategies to Improve Efficacy and Tolerance:

   • Add ascorbic acid (vitamin C) to enhance iron absorption when response is poor 1
   • Consider liquid preparations when tablets are not tolerated 1
   • Lower doses (100 mg daily) may be considered if side effects occur 4
   • Alternate-day dosing may improve tolerance while maintaining efficacy 2, 4

3. Parenteral Iron Therapy (Second-line):

   • Indicated when there is:
     • Intolerance to at least two oral preparations 1
     • Non-compliance with oral therapy 1
     • Intestinal malabsorption 1, 2
     • Ongoing blood loss 2
     • Chronic inflammatory conditions (CKD, heart failure, IBD, cancer) 2, 4
   • Available intravenous preparations include iron sucrose, ferric carboxymaltose, and iron dextran 1
   • Note that parenteral iron therapy is painful (when given intramuscularly), expensive, and may cause anaphylactic reactions 1

Special Populations

1. Pregnant Women:

   • Start oral, low-dose (30 mg/day) iron supplements at the first prenatal visit 1
   • For iron deficiency anemia during pregnancy, prescribe 60-120 mg/day of iron 1
   • When hemoglobin normalizes for gestational stage, decrease iron dose to 30 mg/day 1
   • Intravenous iron is indicated during second and third trimesters when oral iron is not effective 2

2. Chronic Kidney Disease (CKD):

   • Monitor hemoglobin at least every three months in patients with GFR <30 ml/min per 1.73 m² 1
   • Complete workup for anemia including iron studies if hemoglobin <12 g/dl for women or <13 g/dl for men 1
   • Treat iron deficiency if identified 1
   • Consider erythropoietin or analogue if anemia persists despite iron therapy 1

3. Cancer-Related Anemia:

   • Consider erythropoiesis-stimulating agents (ESAs) for patients receiving palliative, myelosuppressive chemotherapy with Hb <10 g/dL without absolute iron deficiency 1
   • Monitor hemoglobin trends weekly initially when using ESAs 1
   • ESAs are not indicated for patients receiving myelosuppressive chemotherapy when the anticipated outcome is cure 1

Follow-up and Monitoring

• The hemoglobin concentration should rise by 2 g/dL after 3-4 weeks of oral iron therapy 1
• Failure to respond is usually due to poor compliance, misdiagnosis, continued blood loss, or malabsorption 1
• Once normalized, monitor hemoglobin concentration and red cell indices every three months for one year, then after a further year 1
• Additional oral iron should be given if hemoglobin or MCV falls below normal 1
• Further investigation is necessary if hemoglobin and MCV cannot be maintained with iron supplementation 1

Common Pitfalls and Caveats

• Failure to identify and treat the underlying cause of anemia can lead to recurrence 1, 2
• Gastrointestinal side effects from oral iron therapy often reduce compliance 5
• Transfused red blood cells do not immediately correct iron deficiency as the iron is not immediately available for erythropoiesis 1
• In women of African, Mediterranean, or Southeast Asian ancestry, mild anemia unresponsive to iron therapy may be due to thalassemia minor or sickle cell trait 1
• Patients with severe co-morbidity should be carefully evaluated before extensive investigation, especially if results would not influence management 1