Agents Used in Anemias Flashcards
What is the most common cause of chronic anemia?
- what do cells in these patients look like?
- Symptoms?
Iron Deficiency
Cells:
- Microcytic and Hypochromic
Symptoms:
- Pale, Fatigue, Dizziness, Tachycardia, Vasodilation
Why is only a small amount of iron lost from the blood each day?
- who is at the greatest risk for non-pathologic deficiency of iron?
- where is the most common place to lose iron via a pathologic process?
Why only a small amt. lost:
- Iron is recycled from old and damaged RBCs
Non-Pathologic:
- Growing Children
- Pregnant or Menestrating Womean
Pathologic:
- G.I. bleed (check for occult bleeding)
What should you give most patients with an iron deficiency?
- What dosage is used, why?
- For how long?
Ferrous Sulfate and Ferrous Gluconate
**Note: only ferrous forms of iron should be used to treat because on Fe++ can be absorbed
Dosage:
- 200-400 mg (PO) Elemental Iron in the above substances daily for rapid correction, because 50-100mg of iron can be incorporated into Hgb daily and only 25% of the supplement will be absorbed.
How long:
- continue for 3-6 months after correction to completely replenish iron stores
What are some side effects of treating someone with Ferrous Sulfate or Ferrous Gluconate?
- what can you do to attenuate this?
- Nausea
- Epigastric Discomfort
- Abdominal Cramps
- Constipation
- Diarrhea
Prevention of Toxic Effects:
- Lower Daily Dose
- Take with meals or After Meals
- Change Salt Formulation
How might oral therapy with iron supplements obscure Dx or continued G.I. blood loss?
Pts. can develop black stools like you do with G.I. bleeds
What are the indications for giving someone iron parenterally, other than not being able to tolerate oral dosing?
In cases of Extensive Iron loss Anemia may not be able to be managed by oral iron alone.
e. g:
- Renal disease requiring hemodialysis and EPO treatment
- Postgastrectomy conditions
- Small bowel resection
- Inflammatory Bowel Disease
- Malabsorption sydromes
(Essentially, ANYONE that has small intestine issues will likely need the drug parenterally)
What is the major treatment challenge associated with giving someone iron parenterally?
- what drug do they give when iron is given IV or IM?
Serious Dose-Dependent Toxicity
Drug:
- Iron Dextran (IV and IM) - Sodium Gluconate Complex [Ferriecit]
What are some of the possible toxic effects of Parenteral Iron Therapy with dextran?
• how can these effects be attenuated?
Effects:
• Headache, Nausea, Vomiting
• Flushing, Urticaria, Bronchospasm
• Anaphylaxis
Attenuation:
• Give a small Test Dose
• Get a history of allergies
• Use other preparations that are less likely to cause hypersensitivity reactions
What tests do we run to assure that iron overload doesn’t happen?
- Serum Ferritin
* Transferrin Saturation - (total serum iron) / (TIBC)
What effects are caused by acute iron toxicity?
• What would you give to counteract these effects?
Effects:
Necrotizing Gastroenteritis
• Abdominal Pain, Vomiting, Bloody Diarrhea
• SHOCK, lethargy
Initial Improvement followed by severe METABOLIC ACIDOSIS, Coma, and Death
Treatment:
• Whole Bowel Irrigation
• Deferoxamine [Desferal]
What are some of the side effects of Deferoxamine [Desferal]?
• How does it work?
• How is it administered?
Deferoxamine - Iron Chelating Agent that DOES NOT effectively chelate other important trace metals
Administration:
- IV
Side Effects:
- Tachycardia, Hypotension, SHOCK
- Could add to the cardiovascular collapse caused by iron toxicity
- Abdominal Discomfort, Nausea, Vomiting, Diarrhea
How is the chelating agent given for iron toxicity excreted?
• What indication would you have that the drug is being excreted and not just held up in the system?
Chelating Agent:
• Deferoxamine
Excretion:
• Excreted in Urine and Bile
• Gives a RED discoloration
What are the effects of CHRONIC iron toxicity?
- Who does this most commonly occur in?
HEMOCHROMATOSIS
• Excess iron deposited in HEART, LIVER, PANCREAS, etc.
• Potential for organ failure
MOST COMMON:
• pts. with Inherited Hemochromatosis
• pts. with Thalassemia Major that recieve many transfusions over a long period of time
How do we treat CHRONIC iron overload?
PHLEBOTOMY - remove one unit of blood about every week
What type of anemia is caused by B12 deficiency?
• Who is this most commonly seen in?
MEGALOBLASTIC, MACROCYTIC ANEMIA
Most Common:
• Older Adults who have difficulty ABSORBING iron (typically getting sufficient amounts of dietary iron is not the issue)
Symptoms of B12 deficiency.
- Megaloblastic - Red cell precursors halt after 1 or 2 divisions and cytoplasm because less blue (RNA degradation)
- Macrocytic - enlarged RBCs with hypersegments neutrophils
- NEUROLOGIC symptoms - Paresthesias in peripheral nerves and weakness progressing to spasticity, ataxia, and CNS issues
T or F: correction of B12 deficiency will correct any neurologic symptoms such Ataxia or Paresthesias caused by the deficit
False, while supplementing B12 back into the diet will likely stop the progression, any damage that has been done is usually permanent
What are some common causes of malabsorption of B12?
• Pernicious Anemia • Partial or Total Gastectomy • Inflammatory Bowel Disease • Small Bowel Resection (other malabsorption syndromes)
Rare cause of B12 deficiency include:
• Bacterial Overgrowth in the Small Bowel
• Chronic Pancreatitis
• Thyroid Disease
• Intrinsic factor/ IF-B12 receptor deficiency in kids
Rare cause of B12 deficiency include:
• Bacterial Overgrowth in the Small Bowel
• Chronic Pancreatitis
• Thyroid Disease
• Intrinsic factor/ IF-B12 receptor deficiency in kids
What is the treatment for a pt. with a B12 deficiency?
- which of the two is preferred?
Parenteral (INTRAMUSCULAR) injection of B12
Specifically:
- Cyanocobalamin
- Hydroxocobalamin
