Hematological Pharm Flashcards
where is majority of the iron in the body found?
70% is found in hemoglobin
what is heme iron essential for?
muscle myoglobin, catalase, perosidase, cytochromes
where is iron stored in?
- reticuloendothelial cells
- Hepatocytes
- intestinal cells as ferritin
- hemosiderin
what is iron stored in the intestinal cells as
ferritin
where is iron absorbed most through?
intestine
what state of iron is more readily absorbed
Fe2+ is more absorbed than ferric state (Fe3+)
what acids promote the absorption of ferrous iron
gastric acid and asocrbic acid
when is iron oxidized to ferric iron
in the intestinal cell
what happens after iron is transferred into ferric iron
- stored as ferritin
- transported to other tissues
what is ferric iron transported in the plasma bound to
glycoprotein transferrin
iron storage is regulated at
the level of absorption
what happens to transferrin receptors when plasma iron concentrations are low
transferrin receptors increase which reduce tissue iron storage
when iron stores are high, what happens to intestinal absorption
decreased intestinal absorption
what happens to transferrin receptors when iron stores are high
tranferrin receptors decrease causing low cellular uptake
what is the order (lowest to highest) of iron by weight
for sulfate, gluconate, fumarate
gluconate < sulfate < fumarate
what percent of PO iron is actually absorbed
25%
how long can iron treatment take
3-6 months
what is the typical PO dose of iron?
65-200mg iron/day
Most common side effects of iroin
- GI upset (constipation, cramps, n/v)
- Bronchospasm/uticaria/anaphylaxis
what drug treats iron toxicity
deferoxamine ( Desferal)
systematically or gastric lavage
iron chelating agent
EPO stands fo
epogen
what does EPO tx require
adequate stores of iron
where is epogen produced
in the kidney’s peritubular cells
what is epogen essential for?
reticulocyte production
what stimulates EPO
hypoxia
what is a 2nd gen ESA that has a longer halflife than epoetin alfa
darbepoetin
what is the MOA of EPO
- increases the rate of proliferation & differentiation in erythroid precursor cells
- in th ebone marrow
- increase release of reticulocytes from marrow
- increase hemoglobin synthesis
what does EPO tranform erythroid progenitor cells into
proerythroblasts
what does EPO do
- increase proliferation & differentiation of erythroid precurosor cells
- transformation of erythroid progenitor to proerythroblast
- increase release of reticulocytes
- increase hemoglobin synthesis
what are the 4 therapeutic uses of EPO
- acquired immune deficiency syndrome treated with zidovudine AZT
- Cancer pts undergoing chemotherapy
- renal failure pts
- surgical pts to reduce the ened for transfusions
what is the onset of EPO when used for surgical pts to reduce the need for transfusion
2-6 weeks
what are the 2 MC side effects of EPO
HTN and thrombotic complications
what are other side effects of EPO
- seizure
- headache
- stroke
- chf
- hemodialysis graft occlusoin
- increased risk of death and serious CV
Vitamin B12 is a (——-) containing moleculue
cobalt containing
what coenzyme is essential for the production of methionine and S-adenosylmethionine to producte tetrahyrofolate
methylcobalamin
what does deficiency leads to production of abnormal fatty acids
Vitamin B12
what is the pharmacologic type of vitamin B12
Cyanocobalamin or hydroxocobalamin (alpharedisol)
what does vitamin B12 complex with in the stomach
intrinsic factor (secreted by parietal cells)
where is intrinsic factor vitamin B12 complex absorbed
active transport in the distal ileum
where is vitamin b12 stored
in the hepatocytes
what i
