Pharm of Anemia; Hematopoietic GFs Flashcards
(53 cards)
Vitamin B12 deficiency
can lead to megaloblastic anemia, GI sxs, neuro abnorms
chief dietary source of VitB12
meat, eggs, dairy
Common signs of anemia
Pallor, fatigue, dizziness, extertional dyspnea, other generalized sx of tissue hypoxia, & CV adaptations such as tachycardia, increased CO and vasodilation
Absence of adequate iron leads to what type of anemia?
Microcytic hypochromic anemia - small erythrocytes with insufficient hemoglobin are formed
Iron absorption
Duodenum & prox jejuni my
When iron stores are high/iron requirements are low
Absorbed iron is diverted into ferritin in the intestinal epithelial mucosal cells for storage
Increased concentration of serum transferrin is associated with
Iron store depletion and iron deficiency anemia
Iron storage
As ferritin (complex of iron and apo-ferritin)
High levels of free iron stimulate production of apoferritin to reduce
Iron toxicity
Oral iron therapy
Only ferrous salts should be used bc ferrous iron is most efficiently absorbed
-ferrous sulfate, ferrous gluconate, ferrous karate
Ferrous salts adverse effects
Nausea, epigastric discomfort, abd cramps, constipation, black stools and diarrhea
Iron dextran
Par enteral iron therapy
-IV infusion -> can admin at higher dose
Adverse effects include: HA, light-headed mess, fever, athralgias, N/V, back pain, flushing, urticaria, bronchospasm, anaphylaxis and death
Sodium ferry gluconate complex and iron-sucrose complex
Parenteral iron therapy
Only IV
Less likely to cause hypersensitivity rxns
Acute iron toxicity
Young children who accidentally ingest iron tablets
-sx: necrotizing gastroenteritis, accompained by vomiting and abd pain and bloody diarrhea followed by shock, lethargy, dyspnea
-followed by severe metabolic acidosis, coma, death
Tx= parenteral deferoxamine
Chronic iron toxicity
Excess iron deposits in heart, liver, pancreas, & other organs
-most common in pts with inherited hemochromatosis & pts who receive many red cell transfusions over a long period of time
Chronic iron toxicity tx
Intermittent phlebotomy
-oral iron chelator deferasirox reduces liver iron concentrations
Vitamin B12 (Cobalamin) deficiency
Leads to Megaloblastic anemia (take 5 yrs to develop if absorption stopped completely), GI sx and neuro abnorms
-stored primarily in the liver
B12 absorption
Absorbed after complexing with intrinsic factor (secreted by parietal cells); absorbed in distal ileum
-after absorption, B12 transported by transcobalamin I,II, III
2 enzymatic rxns require B12
Synthesis of AA methionine & synthesis of succinyl-CoA
B12 deficiency causes
- Accumulation of N5-methylTHF and depletion of THF
- accumulation of homocysteine -> incr serum levels
- methylmalonic acid and methylmalonyl-CoA accumulate
Clinical manifestations of B12 deficiency
Megaloblastic, macrocytic anemia often with associated mild or mod leukopenia or thrombocytopenia and a characteristic hypercellular BM with an accumulation of Megaloblastic erythroid and other precursor cells
-neurologic syndrome associated with B12 def begins with paresthesias and peripheral nerves and weakness and progresses to spasticity, ataxia, & other CNS dysfxns
Folic acid
Required for synthesis of AAs, purines and DNA
Major consequence of folic acid deficiency
Anemia
-cause of congenital malformations in newborns and may play a role in vascular dz
Richest sources of folic acid
Yeast, liver, kidney, green veggies
