Flashcards in Anemia: Hematopoietic Growth Factors, Myeloid Growth Factors, Megakaryocyte growth factors, Sickle Cell Deck (10)
Next in the anemia section we will discuss Hematopoietic growth factors. Several growth factors produced by recombinant DNA technology have been approved to treat patients with blood cell deficiencies. The first is erythropoietin. What are the pharmacodynamics for this?
Erythropoietin is produced in the kidney
--in response to tissue hypoxia and this will correct anemia
Normally an inverse relationship exists between the hematocrit or hemoglobin levels and the serum erythropoietin level.
As the hematocrit and hemoglobin levels fall and anemia becomes more severe the serum erythropoietin level rises
What is the most important exception to the inverse relationship?
Anemia of chronic renal failure
--erythropoietin levels are usually low because the kidneys can not produce the growth factor
---these patients are most likely to respond to treatment with exogenous erythropoietin
What is darbepoetin?
Long acting version of erythropoietin that differs from erythropoietin by addition of two carbohydrate chains
--decreased clearance and a half life three times that of erythropoietin
What is a common adverse effect of erythropoietin?
Next drug is myeloid growth factors for anemia. Includes two drugs Filgrastim and Sargramostin. How do these drugs work?
Stimulate production and function of neutrophils
Also stimulate production of other myeloid and megakaryocyte progenitors
Myeloid growth factors stimulate proliferation and differentiation by interacting with specific receptors on various myeloid progenitor cells. These receptors are members of what?
Both drugs for growth factors are used for what?
Accelerate recovery of neutrophils after cancer chemotherapy and to treat other forms of secondary and primary neutropenia
The next growth factor has to do with megakaryocyte growth factors. Interleukin-11, what does this drug do?
Stimulates growth of primitive megakaryocytic progenitors and increases the number of peripheral platelets.
prior episode of thrombocytopenia after a cycle of cancer chemotherapy
(reduces the need for platelet transfusions)