Pharm: Anemias Flashcards
What is the most common cause of chronic anemia?
Iron Deficiency
What are the common symptoms of iron def?
pallor, fatigue, dizziness, exertional dyspnea, generalized features of tissue hypoxia, cv adaptations to iron def.
Without adequate iron, what happens to the cells?
they form microcytic hypochromic anemia
whose iron doses should be increased?
children, pregnant or menstruating women
what is the most common cause of iron def in men and postmen women? men women?
GI bleeding
menstruation
What are the three drugs used for oral iron supplementation?
ferrous sulfate, ferrous gluconate, ferrous fumarate
what percentage of oral iron can be absorbed? as such how much should be adminstered per day?
25%
200-400 mg of iron should be given per day
what are the toxic effects of oral iron therapy?
nausea, epigastric discomfort, abdominal cramps, constipation and diarrhea. stools turn black
what is the way to parenterally administer iron?
iron dextran
when would iv admin be used?
advanced chronic renal disease requiring dialysis and tx with epo postgastrectomy previous small bowel resection ibs involved proximal small bowel malabsorption
what are the challenges to iv tx of iron deficiency?
there is a serious dose-dependent toxicity
how do we work to prevent the toxicity of iv admin of iron dextran for iron deficiency?
colloidal formulations (carbs surrounding a core of iron oxyhydroxide) iron dextran
what are the toxic effects of iv iron therapy?
headache, light-headed, fever, arthralgias, nausea, vomiting, back pain, urticaria, bronchospasm and sometimes anaphylaxis
what is acute iron toxicity in young children?
iron tablets look like candy (takes about 10 pills)
leads to necrotizing gastroenteritis (vomiting, bloody diarrhea, shock)
how do you detox from acute iron toxicity?
whole bowel irrigation (charcoal will not work)
deferoxamine (iron-chelating compound)
when does hemochromatosis commonly occur?
inherited or ppl with chronic red cell transfusions
how can you treat chronic iron tox?
deferasirox given orally (to treat due to blood transfusions)
in the absence of anemia, what is the msot common treatment for chronic iron overload?
phlebotomy
what does b12 deficiency lead to?
megaloblastic anemia, gi symptoms and neurologic abnormalities
what are symptoms of b12 def?
megaloblastic macrocytic anemia neurologic syndromes (paresthesias in peripheral nerves and weakeness and progressed to spasticity ataxia and other cns dysfunctions)
what are common causes of b12 def?
pernicious anemia or gastrectomy
what are some rare causes of b12 def?
bacterial overgrowth of small bowel
chronic pancreatitis
thyroid disease
what vitamins are frequently used to treat b12 def?
cyanocobalamin and hydroxocobalamin (preferred)
When is folic acid def commonly found?
in alcoholics and those with liver disease, poor diet and diminished hepatic stoarge of folates
what is the oral therapy used in folic acid
1 mg of folic acid daily is sufficient
what are drug-induced deficiencies of folic acid?
methotrexate, trimethoprim and pryimethamine (the latter two are less likely)
phenytoin reduced folate uptake
leucovorin (which modulates 5-fu function)
what three minerals are linked to depression with there are depressed levels?
zinc, magnesium and folate
what is levomofolate?
biologically active form of folic acid found inthe circulation. readily crosses the blood brain barrier where it modulates the production of serotonin, norep and dopamine.
what is epoietin alfa?
agonist of epoR, which stimulates the erythroid proliferation and differentiation, tx of anemia and chronic renal failure, hiv, infxn cancer, and prematurity
where is endogenous epo primarily produced
kidney
what are more common non-life threatening effects of epo supplementation
htn, heachaches, arthralgias, nausea
in addition to prematurity, children treated for hiv with what drug benefit from epo tx?
zidovudine (retrovir)
what are the myeloid growth factors?
g-csf, gm-csf and pegfilgrastim
what does g-csf do?
stimulates proliferation and differentiatoin of progenitors already committed to the neutrophil lineage. actiavtes the phagocytic nature of neutrophils, and mobilizes hema stem cells to increase in concentration in peripheral blood (used to collect for hsct)
what does gm-csf do
same as g-csf except that it targets multipotential stem cells, allowing a rise in erythroid and megakaryocyte progenitors
how does gm-csf act with il2
stimulates mature t cell proliferation
what is oprelvekin?
an il11 type that activates il11 receptors, stimulating growth of multiple lymphoid and myeloid cells including megakaryocyte progenitors and increases number of circulating platelets and neutrophils
what are the toxicities of oprelvekin?
anemia, dyspnea, and transient atrial arrhythmias
what is romiplostin?
tpo-mimetic fusion protein that contains two identical single-chain subunits, each consisting of human igg1 fc domain. remains active longer than endogenous tpo
