4- Anemia and Hematopoiesis Flashcards
Name three classes of medications that can reduce iron absorption
- Acid reducing meds
- Antibiotics
- Fiber supplements
Name two classes of antibiotics known to reduce iron absorption
Tetracyclines (doxycycline, minocycline, tigecycline)
Fluroquinolones (ciprofloxacin, levofloxacin, moxifloxacin, etc)
Discuss different types of acid reducing medications and their effect on iron absorption
H2 blockers (Zantac, etc)
Proton Pump Inhibitors (Prilosec)
Antacids (TUMS, calcium)
Reduce iron absorption b/c need acidic environment
Name the types of oral iron supplementation
Ferrous sulfate, gumarate, gluconate Polysaccharide iron complex (Niferex) Carbonyl iron (Ferralet)
What are the side effects of oral iron therapy?
Constipation, nausea/ vomiting, stomach cramping, heartburn, black tarry stools, stained teeth
Directly related to amount of iron ingested
Iron deficiency causes what type of anemia?
microcytic, hypochromic anemia
Where and how is iron stored in the body?
Reticuloendothelial cells, hepatocytes, and intestinal cells as ferritin and hemosiderin
What form of iron is absorbed and where is it absorbed?
Fe 2+ (Fe2+ intwo the cell) in the duodenum via enterocytes
How does iron travel in the bloodstream?
Bound to transferrin (glycoprotein)
True or false: there are mechanisms to actively eliminate iron from the body
FALSE.
There are no active mechanisms to eliminate iron from the body besides bleeding
Name 4 general mechanisms of iron deficiency anemia
- Bleeding
- Dietary deficiency
- Malabsorption syndrome
- Increased iron demands (pregnancy)
Discuss the general characteristics of oral iron agents
- iron content: gluconate 12%, sulfate 20%, and fumarate 30%
- 25% orally administered iron absorbed
- Requires 3-6 months to replenish stores
What are some reasons oral iron therapy might not work?
- ongoing blood loss
- non-compliance
- absorbance issues: GI diseases such as celiac & atrophic gastritis/ H. pylori
- Concurrent folate/ B12 deficiency
When is parenteral iron given?
- significant blood loss
- intolerance to oral therapy
- absorption issues
- allergies to oral
- prep for erythropoietin therapy
Ferrlecit (class, administration, uses)
Class: ferric gluconate complex
Admin: IV
Uses: hemodialysis patients with erythropoietin therapy
Venofer (class, administration, uses)
Class: Iron sucrose
Admin: IV
Uses: hemodialysis patients with erythropoietin
Iron dextran (class, admin, uses, adverse reaction)
Class: parenteral iron
Admin: IM or IV
Uses: unable to take oral iron
Adverse rxn: anaphylactic reaction, nausea, diarrhea, injection site reaction
Generally how does megaloblastic anemia occur?
Impaired DNA synthesis affecting rapidly growing cells (RBC’s)
Deficiency in what vitamins can cause megaloblastic anemia?
Vitamin B12 (cobalamin) and folic acid (B9)
Describe the mechanism of pernicious anemia
lack of intrinsic factor due to GI destruction of parietal cells - inhibited B12 absorption
Causes of vitamin B12 deficiency
- pernicious anemia
- achlorhydria (decreased gastric acid)
- Gastritis/ H. pylori infection
- Proton pump inhibitors, metformin
- Alcohol abuse
- nitrous oxide
Deferoxamine (Class, Admin, Uses)
Class: iron-chelating agent
Admin: parenteral/ gastric lavage
Uses: txt for iron toxicity
What is the txt for B12 deficiency?
Oral or intranasal gel (Nascolbal) B12 therapy
How does dosing differ for B12 therapy for diet deficiency vs. impaired absorption/ pernicous anemia
Diet: 1-10 mcg daily
Absorption: 1000 mcg (1mg) daily
