AntiAnemic Flashcards
(20 cards)
What are the main types of anemia, and how are they classified based on etiology?
• Blood loss (acute or chronic)
• Increased destruction (hemolytic anemia, malaria)
• Decreased production (bone marrow damage, medication-induced)
• Anemia of inflammation
• Nutrient/hormone deficiencies (Iron, Vitamin B12, Folate, Erythropoietin, Vitamin C)
What are the clinical signs of iron deficiency anemia and what hemodynamic change can occur as a result?
• Signs: Pallor, fatigue, dizziness, exertional dyspnea, tissue hypoxia
• Hemodynamic change: Decreased blood viscosity → decreased vascular resistance → increased venous return → increased cardiac output
What are the causes of iron deficiency anemia? (List all categories.)
• Bleeding: Chronic GI bleeding, heavy menstruation, acute ≥2L blood loss
• Increased demand: Pregnancy, infancy
• Malabsorption: GI disease, antacids, bariatric surgery
• Dietary deficiency: Alcoholism, vegetarian diets
• B12/Folate therapy: Enhanced RBC production increases iron demand
How is iron absorbed, transported, and stored in the body? Include the role of hepcidin.
• Absorption: Through DMT-1 channel and HCP1
• Transport: Via transferrin to bone marrow
• Storage: In liver, released by ferroportin
• Hepcidin: Blocks absorption and liver release of iron; low iron → low hepcidin
What are the clinical indications for oral iron therapy, and what are its pharmacokinetics and adverse effects?
• Indications: Adequate GI absorption, not on hemodialysis or erythropoietin
• Pharmacokinetics: Continue therapy 3–6 months after correction
• Adverse effects: GI distress, nausea, vomiting, black stools, hypersensitivity, iron overdose (treat with deferoxamine, NOT charcoal)
When is parenteral iron therapy indicated, and what are the risks associated with its use?
• Indications: Intolerance to oral iron, severe anemia
• Risks: Anaphylaxis (iron dextran), hypotension (ferumoxytol, iron sucrose), skin staining, iron overload, infection promotion
Compare the key characteristics (administration, adverse effects) of the four main parenteral iron preparations.
Drug Key Info Adverse Effects
Iron Dextran IV/IM; test dose required Anaphylaxis risk, skin staining
Ferumoxytol IV; MRI interference; no test dose Hypotension, allergic reactions
Iron Sucrose IV; multiple small doses Leg cramps, hypotension
Ferric Gluconate IV; possible test dose Hypertension, tachycardia
What vitamins assist in iron absorption, and what drugs can interfere with iron therapy?
• Assists: Vitamin C (keeps iron in Fe²⁺ state)
• Drugs decreasing iron absorption: Antacids, H2 blockers, PPIs, cholestyramine, tetracyclines
• Drugs affected by iron: Levodopa, levothyroxine, penicillamine, fluoroquinolones
How is acute and chronic iron toxicity treated?
• Acute: Whole bowel irrigation (NOT activated charcoal)
• Chronic: Phlebotomy (hemochromatosis); chelation with deferasirox (oral) or deferoxamine (IV)
What are the differences between deferasirox and deferoxamine for iron chelation therapy?
Characteristic Deferasirox (oral) Deferoxamine (IV)
Binding ratio 2:1 (iron:drug) 1:1
Excretion Urinary Urinary
Half-life 8–16 hours Biphasic
Adverse effects GI issues, rash Orange urine, hypotension, renal/oto/pulmonary toxicity
What are the major biochemical roles of Vitamin B12 and folate in the body?
• Vitamin B12: Formation of tetrahydrofolate (THF), conversion of methylmalonate CoA to succinyl CoA for ATP
• Folate: One-carbon transfers (e.g., glycine → serine, formiminoglutamate → glutamate)
What are the clinical and laboratory features of Vitamin B12 deficiency?
• Clinical: Megaloblastic anemia, leukopenia, thrombocytopenia, peripheral neuropathy, ataxia
• Labs: High methylmalonic acid (MMA), hypersegmented neutrophils
How does the methyl-folate trap contribute to megaloblastic anemia in Vitamin B12 deficiency?
Without B12, folate becomes trapped as methyl-THF and can’t regenerate THF, leading to impaired DNA synthesis and megaloblastic anemia. Giving folate can correct anemia but NOT neuropathy.
What are the causes of Vitamin B12 deficiency, and how is it treated?
• Causes: Lack of intrinsic factor (pernicious anemia), PPI use, GI surgery, ileal disease, dietary deficiency
• Treatment: Parenteral hydroxocobalamin preferred over cyanocobalamin (higher binding and longer half-life)
What are the causes of folate deficiency, and how is it treated?
• Causes: Inadequate intake, alcohol dependence, liver disease, malabsorption, dialysis, antifolate drugs (methotrexate)
• Treatment: Oral folic acid 1 mg/day; leucovorin (folinic acid) for methotrexate toxicity
How do you differentiate Vitamin B12 deficiency from folate deficiency using laboratory tests?
• B12 deficiency: Elevated methylmalonic acid (MMA) and homocysteine
• Folate deficiency: Elevated homocysteine only (normal MMA)
What are the differences between oral and parenteral Vitamin B12 therapy?
Characteristic Oral B12 Parenteral B12
Use Only in specific cases (e.g., mild deficiency, patient preference) Preferred for most, esp. pernicious anemia
Dosing 1000 µg/day 100–1000 µg IM daily/other day (loading), then monthly
What hematologic abnormalities are associated with iron, B12, and folate deficiencies?
Deficiency RBC Morphology
Iron Microcytic, hypochromic
Vitamin B12 Macrocytic
Folate Macrocytic
How does erythropoietin deficiency contribute to anemia, and what are therapeutic options?
• Cause: CKD, critical illness, chemotherapy, HIV treatment
• Treatment: Epoetin alpha (IV, 3x/week) or darbepoetin alpha (longer half-life, weekly)
What are the pharmacodynamics and major adverse effects of Epoetin alpha?
• Mechanism: Binds EPO receptors → stimulates RBC production
• Adverse effects: Hypertension, thrombosis, hypersensitivity, risk of “blood doping”
