BLOOD_GOUT Flashcards
Vitamin B12
Cobalamin
Results from either folate or vitamin B12 deficiency anemia
Megaloblastic anemia
A deficiency in serum hemoglobin and erythrocytes in which the erythrocytes are abnormally small. Often caused by iron deficiency
Microcytic anemia
The most common cause of erythrocyte deficiency, or anemia, is ____ substances required for normal production of erythrocytes.
insufficient supply of iron, vitamin B12, or folic acid
Caused by iron deficiency. Most common type of anemia.
Microcytic hypochromic anemia
The most common type of vitamin B12 deficiency anemia. Caused by a defect in the synthesis of intrinsic factor, a protein required for efficient absorption of dietary vitamin B12, or by surgical removal of that part of the stomach that secretes intrinsic factor.
Pernicious anemia
Role of Iron
• transport protein:
• a storage protein
- Transferrin
- Ferritin
Pregnancy Daily Requirements
• Iron:
• Folic Acid:
- Iron: 30-60 mg
* Folic Acid: 400 µg (0.4 mg)
is most common in children includes necrotizing gastroenteritis, shock, metabolic
acidosis, coma, and death may result
Acute iron intoxication
known as hemochromatosis, damages the organs that store excess iron (heart, liver, pancreas).
Chronic iron overload
Removal of unabsorbed tablets from the gut, correction of acid-base and electrolyte abnormalities, and parenteral administration of deferoxamine, which chelates circulating iron.
Treatment of acute iron intoxication
Treatment of chronic iron toxicity
- Treatment of the genetic form of hemochromatosis is usually by phlebotomy.
- Hemochromatosis that is due to frequent transfusions is treated with parenteral deferoxamine or with the newer oral iron chelator deferasirox.
Produced only by bacteria
• Intrinsic factor: a product of the parietal cells of the stomach.
• Plasma transport → transcobalamin II
Vitamin B12 (cobalamin)
Where is Vitamin B12 (cobalamin) stored?
2 forms of Vitamin B12 (cobalamin)
- liver
- cyanocobalamin and hydroxocobalamin
Administration of folic acid to patients with vitamin B12deficiency helps refill the ___ and partially or fully corrects the anemia.
tetrahydrofolate pool
The major application of Vitamin B12 is in the treatment of naturally occurring
- pernicious anemia
- anemia caused by gastric resection
Like vitamin B12, folic acid is required for normal DNA synthesis, and its deficiency usually presents as
.
megaloblastic anemia
Deficiency of folic acid during pregnancy increases the risk of
neural tube defects in the fetus
Because maternal folic acid deficiency is associated with increased risk of neural tube defects in the fetus, folic acid supplementation is recommended ____ and ___ pregnancy.
before, during
is produced by the kidney; reduction in its synthesis underlies the anemia of renal failure.
Erythropoietin
Routinely used for the anemia associated with renal failure
• Sometimes effective for patients with other forms of anemia
– eg, primary bone marrow disorders or anemias secondary to cancer chemotherapy or HIV treatment, bone marrow transplantation, AIDS, or cancer
ERYTHROPOIESIS-STIMULATING AGENTS (ESAS)
a glycosylated form of erythropoietin, has a much longer half-life.
Darbepoetin alfa
The most common complications of ESA therapy are
hypertension and thrombosis
The serum hemoglobin concentration of patients treated with an ESA should not exceed ____ because hemoglobin concentrations above this target have been
linked to an increased rate of mortality and cardiovascular events.
12 g/dL
stimulate the production and function of neutrophils
- Filgrastim (granulocyte colony-stimulating factor; G-CSF)
- sargramostim (granulocyte-macrophage colony-stimulating factor; GM-CSF)
- also stimulates the production of other myeloid and megakaryocyte progenitors.
- Together with, to a lesser degree of GM-CSF mobilize hematopoietic stem cells (ie, increase their concentration in peripheral blood).
- GM-CSF
- G-CSF
The toxicity of G-CSF
sometimes causes bone pain
The toxicity of GM-CSF
fever, arthralgias, and capillary damage with edema
• stimulates the growth of primitive megakaryocytic progenitors and increases the
number of peripheral platelets.
• is used for the treatment of patients who have had a prior episode of thrombocytopenia after a cycle of cancer chemotherapy.
Oprelvekin (interleukin-11 [IL-11])
A 23-year-old pregnant woman is referred by her obstetrician for evaluation of anemia. She is in her fourth month of pregnancy and has no history of anemia; her grandfather
had pernicious anemia. Her hemoglobin is 10 g/dL(normal, 12–16 g/dL).
If this woman has macrocytic anemia, an increased serum concentration of transferrin, and a normal serum concentration of vitamin B12, the most likely cause of her anemia is deficiency of?
Folic acid
If the patient in question 1 had the deficiency identified, her infant would have a higher than normal risk of which of the following?
(A) Cardiac abnormality (B) Congenital neutropenia (C) Kidney damage (D) Limb deformity (E) Neural tube defect
Neural tube defect
The laboratory data for your pregnant patient indicate that she does not have macrocytic anemia but rather microcytic anemia. Optimal treatment of normocytic or mild microcytic anemia associated with pregnancy uses which of the following?
(A) A high-fiber diet (B) Erythropoietin injections (C) Ferrous sulfate tablets (D) Folic acid supplements (E) Hydroxocobalamin injections
Ferrous sulfate tablets
If this patient has a young child at home and is taking iron-containing prenatal supplements, she should be warned that they are a common source of accidental poisoning in young children and advised to make a special effort to keep these pills out of her child’s reach. Toxicity associated with acute iron poisoning usually includes which of the following?
(A) Dizziness, hypertension, and cerebral hemorrhage
(B) Hyperthermia, delirium, and coma
(C) Hypotension, cardiac arrhythmias, and seizures
(D) Necrotizing gastroenteritis, shock, and metabolic acidosis
(E) Severe hepatic injury, encephalitis, and coma
Necrotizing gastroenteritis, shock, and metabolic acidosis
An endogenous anticlotting protein that irreversibly inactivates thrombin and factor Xa. Its enzymatic action is markedly accelerated by the heparins.
Antithrombin III
- Fractionated preparations of heparin of molecular weight
- Unfractionated heparin has a molecular weight range of
- 2000—6000
- 5000—30,000
- treatment of both venous and arterial thrombosis
- used primarily for treatment of arterial disease
- Anticoagulant and thrombolytic drugs
- Antiplatelet drugs
3 major types of anticoagulants are available:
1. Heparin and related products – must be used parenterally 2. Direct thrombin and factor X inhibitors – used parenterally or orally 3. Coumarin derivatives (eg, warfarin) – oral
Heparin is given intravenously or subcutaneously to avoid the risk of ___ associated with intramuscular injection.
hematoma
is a small synthetic drug that contains the biologically active pentasaccharide present in unfractionated and LMW heparins. It is administered subcutaneously once daily.
Fondaparinux
Unfractionated heparin binds to endogenous ____ via a key pentasaccharide sequence.
antithrombin III (ATIII)
The action of heparin is monitored with the activated ___ laboratory test.
partial thromboplastin time (aPTT)
the short-chain heparin–ATIII and fondaparinux– ATIII complexes provide a more selective action because they fail to affect ___.
thrombin
When to use heparin?
Because of its rapid effect, heparin is used when anticoagulation is needed immediately (eg, when starting therapy).
Common of heparin uses include treatment of:
– DVT
– Pulmonary embolism
– Acute myocardial infarction
Heparin is used in combination with thrombolytics for ___ and in combination with glycoprotein IIb/IIIa inhibitors during angioplasty and placement of coronary stents.
revascularization
is the most common adverse effect of heparin and related molecules
Increased bleeding
can lessen the risk of serious bleeding that can result from excessive unfractionated heparin. Only PARTIALLY reverses the effects of LMW heparins and DOES NOT AFFECT the action of fondaparinux.
Protamine
causes moderate transient thrombocytopenia in many patients and severe
thrombocytopenia and thrombosis (heparin-induced thrombocytopenia or HIT) in a small percentage of patients who produce an ANTIBODY that binds to a complex of heparin and platelet factor 4.
Unfractionated heparin
Prolonged use of unfractionated heparin is associated with
osteoporosis
