Antianemics Flashcards
What is a microcytic anemia?
MCV (mean corpuscular volume)
What is a macrocytic anemia?
MCV >99= large RBCs due to accumulation of precursors for DNA synthesis (which require B12 or folate to carry them through maturation).
*So you will treat a macrocytic anemia with either B12 or folic acid.
How much total iron is in the body?
4 grams
Is iron essential to all cells?
YES and 90% is recycled.
Is iron ever free?
RARELY. It is usually bound to specific proteins bc it is toxic otherwise.
How is iron lost?
It doesn’t have a good mechanism for loss, so it is only lost by exfoliation in the skin or bleeding.
What are the major causes of iron deficiency anemia?
In men due to peptic ulcer and menorrhagia in women.
Also malnutrition, malabsorption, and gastrectomy.
What is the major storage site for iron?
the liver as apoferritin.
What happens if you need more iron?
your body will absorb more.
What happens if you have enough of iron?
your body will not absorb anymore and will be passed along.
How is iron transported in the blood?
via transferrin.
What is the total iron binding capacity?
really synonymous with the amount of transferrin available in the blood.
What are the iron binding proteins in the body?
- hemoglobin= 50-66%
- reticuloendothelial cells (macrophages)= 27% (ferritin and hemosiderin).
- myoglobin= 3-13%
- cytochromes= 2%
- transferrin= 1%
What is the normal saturation % of transferrin?
20-35%
What will the TIBC be if you have an iron deficiency?
High, because there is little iron around, you have many open sites on transferrin.
Will your hematocrit and hemoglobin be normal in slight iron deficiency?
YES
What are the symptoms of iron deficiency?
tired and fatigued
Will your hematocrit (%RBCs) be decreased if you have an iron deficiency ERYTHROPOIESIS?
YES, TIBC saturation will be low and TIBC will be high
**Will your hematocrit be decrease if you have an iron deficiency ANEMIA?
YES along with microcytosis, hypochromia, irregular cell shapes, and sizes.
TIBC saturatoin= low
TIBC= high
You will also have sever fatigue, dizziness, increased HR, dyspnea, CHF and palpitations.
What is the treatment for microcytic anemia?
Restore hemoglobin and RBC production via FERROUS SULFATE, thus increasing iron stores.
** What is iron dextran?
iron supplement administered IM or IV as a large bolus.
** What will acute iron toxicity do to you?
shock, hypovolemia, heart/liver/renal failure due to free iron, also acidosis, coma, or even death.
TIBC>100%
** How do you treat iron toxicity?
test question
deferoxamine= an iron chelator that binds to iron.
Also use emesis, lavage, and sodium-bicarb.
*contraindicated in pregnancy and renal dysfunction.
** What is folic acid?
essential for 1-carbon metabolism of DNA and it is needed in pregnancy to inhibit neural tube disorders in fetus.
What will a deficiency in folic acid lead to?
a deficiency in DNA synthesis.
What is a MEGALOblastic anemia?
any deficiency that involves lack of folic acid or B12, and thus a megaloblastic change in all rapidly dividing cells (i.e. these cells look large).
How does a macrocytic anemia differ from a megaloblastic anemia?
macrocytic does not involve folic acid or vitamin B12 deficiency. Rather alcohol, liver disease, and the drug 5-FU can cause this.
What does methotrexate and trimethoprim do?
inhibit dihydrofolate reductase, thus leading to a folate deficiency
Will methylmalonic acid change in a folate deficiency?
NO it will be normal.
Will methylmalonic acid change in a B12 deficiency?
YES it will go up because it requires B12 to convert it to succinyl-CoA
How do you treat folate deficiency?
Eat leafy green veggies :)
** What would happen if you treat a vitamin B12 deficiency with folate; aka you thought you had a folate deficiency, so you treated with folate?
(BOARD QUESTION)
you will correct the NONneurologic symptoms of B12 deficiency and treat the anemia, but you will still have the neurologic symptoms!!!
***Why do we need vitamin B12 (hydroxocobalamin)?
it is needed for FH4 (TH4) production and used to generate deoxythymidylate (dTMP) for DNA synthesis and also needed for methionine/myelin synthesis (hence neurological).
What will pernicious anemia do?
inhibits the parietal cells of the stomach from secreting intrinsic factor, which is needed for B12 absorption in the ileum. Hence, you will get a B12 deficiency.
Will B12 deficiency cause myelin degeneration and memory loss?
YES. Folate deficiency will NOT though.
How do you test for B12 deficiency/pernicious anemia?
Schilling test
Will oral supplements of vitamin B12 often help if you have a deficiency?
NO, because it is mostly due to a malabsorption issue, so even if you take more, you won’t be able to absorb it. So you must get it IM or IV.
*Remember, this takes a LONG time to develop because the liver has at least a year’s worth of B12 stores.
What important condition will lead to a decrease in erythropoietin (EPO)?
anemia of chronic disease (renal failure) because the kidneys are what produce EPO. Be careful when giving EPO though because too much can cause thrombosis :(
**What is Filgrastim (G-CSF)?
board question
- increases production of neutrophils and enhances mobilization of hematopoietic stem cells into the blood.
- used in recovery from chemo/AIDS/transplantation immunosuppression.
What is Sargramostim?
stimulates growth of stem cells into granulocytes and macrophages.
What is Oprelvekin (IL-11)?
stimulates growth of megakaryocytes and increases number of platelets.
