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Microcytic hypochromic Anemia

A. Iron deficiency anemia

1. Blood loss: menstruation (10-20 mg of iron loss/month), GI bleeding, GU bleeding, trauma, etc., intravscular hemolysis.
2. Insufficient iron intake: menstruating, pregnant, surgical pts, elderly & indigent pts, poor dietary iron intake
3. Impaired absorption: malabsorption
4. RX:  iron rich diet, iron supplement as ferrous sulfate or liquid iron (Fer-in-Sol); IM or IV iron-dextran complex (Imferon) 100-250 mg ,or INFed of 50mg/ml at no more than 2 ml IM/day (first test with 0.5 ml dose), or Dexferrum at 100 mg per dose IV.

*  See below about some points about iron deficiency anemia

B. Sideroblastic anemia

It is characterized by ineffective erythropoiesis anemia with ringed sideroblasts, saturation of serum iron binding capacity (usually approaching 80%), >LDH, & bizarre peripheral smear with hypochromia, distorted red cells, & basophilic stippling.

1. Hereditary or congenital: x linked or autosomal recessive
2. Acquired sideroblastic anemia
   a. Idiopathic refractory sideroblastic anemia
   b. Secondary to: neoplasm (Di Guglielmo's disease erythroleukemia), inflammatory, hematologic, metabolic diseases.
   c. Associated with drugs or toxins: (1) Alcohol. (2) Lead. (3) Chloramphenicol. (4) Anti TB meds: INH. (5) Anti neoplastic alkylating agents as cytophosphamide.

C. Thalassemia hemoglobinopathies / anemia  

Some points about iron deficiency:  
Liz Simmons, MD (Dept. of Hematology/Oncology) July 2003

Diagnosis:

· Ferritin

• < 20 is diagnostic of iron deficiency.
• 20-30 is indicative of borderline iron stores
• May be elevated in chronic inflammatory states/liver disease

· Iron saturation (Helpful but not absolute):

• Affected by oral iron intake: patients should not take MVI with iron or iron tablets within 24 hours of test for reliable results.
• < 5% generally diagnostic of iron deficiency
• 5-10% probable iron deficiency
• >15% More likely anemia of chronic disease

· Indices: MCV usually reduced in proportion to the hemoglobin. Exceptions:

• chronic blood loss accompanied by enough iron ingestion to keep red cells normal sized but not to replete iron stores or keep hemoglobin normal
• Multifactorial (e.g.,
  • combined B12/Fe deficiency, hypothyroidism (MCV higher than expected)
  • hemoglobinopathies (MCV much lower than expected for anemia)

Treatment:

1. For uncomplicated iron deficiency anemia (menstruating female; patients with clear source of iron deficiency anemia):

Iron sulfate (ferrous sulfate) 325 mg three times a day: best tolerated with food. Work up to full dose over a week. Patients should be advised to use stool softener at first sign of constipation. Twice a day is often sufficient, but it may take longer to correct the anemia. Expect 6-8 weeks to normalize hemoglobin. To replace iron stores, continue iron at once daily dose for 6 months after correction of anemia. Do not expect ferritin levels to normalize until then (ferritin reflects iron stores; we don't store iron until we replete our red blood cells). Menstruating women with recurrent or severe iron deficiency should take continued iron supplementation until menopausal (with intermittent evaluation of CBC/ferritin to ensure compliance/maintenance of normal hemoglobin). Some women will do well long term with a multivitamin/iron supplement, but must make sure that above initial treatment is completed.

2. For iron deficiency anemia of unknown cause, same treatment applies, but patients should be evaluated for source of bleeding:

· GI workup mandatory for anyone over 50, consider for those over 40 without a good explanation for iron deficiency; most males at any age should be evaluated for GI blood loss; INCLUDES STOOL FOR OB.

• colonoscopy preferred over sigmoidoscopy, because right sided lesions may be more likely to be associated with bleeding).
• EGD
• Consider UGI/SBFT  xray to rule out small bowel lesions if colonoscopy/EGD noninformative. Should be considered more strongly for patients with recurrent unexplained iron deficiency after adequate primary therapy and for all patients with occult blood positive stools with negative EGD/colon
• GU workup: urinalysis may reveal hematuria due to GU tract tumors.

3. Iron intolerance:
Most patients will be able to tolerate oral iron if they work up to a full dose over several days, take it with food and are prepared to deal with constipation.

If a patient does not tolerate ferrous sulfate, a trial of ferrous gluconate should be given (same dosing). It contains less iron (30 mg), so may take a little longer to work. Niferex tablets (nonformulary, prescription required) contain 50 mg elemental iron and may be tried when ferrous sulfate or gluconate are not tolerated.

4. Intravenous iron
should be reserved for patients who really do not tolerate oral iron after a reasonable trial period (working up to full dose, trying different preparations, as above) or for patients with excessive iron losses due to untreatable causes (huge hiatal hernias, etc.), very severe iron deficiency intolerant to oral iron, but IV iron does not work any faster than oral iron. It has to be broken down to a usable form of iron within the bone marrow and does not begin to work for about 2 weeks.  Expect 6-8 weeks to normalize the hemoglobin. Ferritin levels may abruptly rise and are not helpful in the short run. PDR has a table which gives the total dose of imferon to use based on hemoglobin and weight of patient.

5. When should patient be referred to Hematology?

• Diagnostic uncertainty
• Failure to respond to iron after reasonable therapeutic trial as outlined above
• For consideration of IV iron
• Recurrent, unexplained iron deficiency

We are happy to answer questions that will help with management of these patients via email or phone call.

07172003