Haemopoietic System Flashcards
Drugs
-classes (3) and names (5)
- Agents used in anemias – Iron (Ferrous Sulfate), Folic acid, Vitamin B12 (hydroxocobalamin)
- The haemopoietic growth factors – Epoetin alfa
- The myeloid growth factors – Filgrastim
Absorption, transport and storage of iron
I skipped it
go look at it if you wanna know
Iron - Ferrous Sulfate
- mechanism of action
- indications
- Fe3+ must be converted to Fe2+ for absorption in the GI tract
- absorbed into mucosal cells (jejunum, ileum) –> transported into plasma and stored intracellularly as ferritin
- in plasma it is bound to transferrin
- can only be given orally
-iron deficiency anemia
Iron - Ferrous Sulfate
- clinical toxicity
- antidote
Acute: children accidentally ingest iron tablets
- necrotizing gastroenteritis
- severe metabolic acidosis, shock, coma, death
Chronic
-hemochromatosis
DEFEROXAMINE - binds iron and aluminium
-IV, intramuscular or subcutaneous
Iron - Ferrous Sulfate
-unwanted effects (6)
- pain at the injection site
- diarrhea
- vomiting
- fever
- hearing loss, eye problems
- severe allergic reactions
Vitamin B12
- deficiency leads to…
- absorption and transport
- indications
- megaloblastic anemia, GI symptoms, neurologic abnormalities
- most of the times deficiency is caused due to malabsorption
- absorbed after it complexes with intrinsic factor
- transported to various cells bound to transcobalamin glycoproteins
- excess is stored in the liver
- pernicious anemia (megaloblastic)
- after surgical procedures that remove the site of production of intrinsic factor or of vit. B12 absorption
Folic acid
- deficiency leads to…
- where do we get folic acid from?
- mechanism of action
-megaloblastic anmiea, neurologic syndrome
- humans do not produce folic acid endogenously, we get it from diet
- green leafy vegetables, citrus fruits, animal products…
- oral form is well absorbed
- active uptake by cells, reduce to tetrahydrofolate and by dihydrofolate reductase
- tetrahydrofolate cofactors participate in the synthesis of purine and pyrimidines
Function of Vit. 12 and Folic acid
DNA synthesis
Folic acid
-indications (3)
- megaloblastic anemia
- toxicity of methotrexate
- prophylaxis at hazard from developing folate deficiency (pregnancy)
Epoetin Alfa and Filgrastim
-indications (4)
- patients with chronic renal failure
- cancer patients treated with myelosuprressive cancer chemotherapy
- neutropenia
- anemia
Epoetin Alfa
- unwanted effects (2)
- mechanism of action
- hypertension
- thrombotic complications
- production of erythrocytes
- useful during chronic kidney failure
Filgrastim
- unwanted effects
- why is it used more frequently?
- mechanism of action
- bone pain, which clears when the drug is discontinued
- higher doses –> fever, malaise, myalgias, capillary leak syndrome (peripheral edema and pleural or pericardial effusions
- they are better tolerated
- production of neutrophils
Doptelet – Avatrombopag
- indication
- mechanism of action
- complications
-treatment of thrombocytopenia in adult patients with chronic liver disease who are scheduled to undergo surgery
- thrombopoietin receptor agonist
- stimulates proliferation and differentiation of megakaryocytes from bone marrow progenitor cells resulting in an increased production of platelets
-thrombotic/thromboembolic complications
Why Epoetin Alfa and Filgrastim cannot be given orally?
Because they are peptides and they would be degraded in the stomach
they need to be given subcutaneously or intravenously
