Hematologic Drugs: Module 7 Flashcards
Hematinic Drugs
Examples:
- Iron:
- Vitamin B12:
- Folic acid:
- Erythropoietin agents:
ANEMIA:
Provide building blocks for red blood cell (RBC) production by increasing hemoglobin (necessary for oxygen transport)
- Treat iron deficiency anemia (6 months to correct)
- treat pernicious anemia
- treat megaloblastic anemia due to folic acid deficiency
- treat normocytic anemia; stimulates RBC production (erythropoiesis) [epoetin alfa, darbepoetin alfa]
- low hemoglobin concentration due to decreased RBCs)
Iron:
- Transported in blood bound to?
- 30% stored as _______ or _______ in liver, spleen, bone marrow; used for ________ (RBC production)
- 66% contained in _______
- Deficiency due to?
- Formulations:
- Adverse Effects
- Absorbed in small intestine; dependent on body stores (high stores—-low absorption; low stores—–high absorption); decreased absorption with antacids
- transferrin
- hemosiderine or ferritin
- hemoglobin
- due to blood loss, decreased intake
- don’t vary in absorption; vary in amount of elemental iron supplied; enteric-coated= decreased absorption as iron not released until after leaves small intestine [ferrous fumarate, ferrous gluconate, ferrous sulfate]
- gastric irritation, constipation
Hematinic drugs
-Iron:
- Transported in blood bound to?
- 30% stored as _______ or _______ in liver, spleen, bone marrow; used for ________ (RBC production)
- 66% contained in _______
- Deficiency due to?
- Formulations:
- Adverse Effects
- Absorbed in small intestine; dependent on body stores (high stores—-low absorption; low stores—–high absorption); decreased absorption with antacids
- transferrin
- hemosiderine or ferritin
- hemoglobin
- due to blood loss, decreased intake
- don’t vary in absorption; vary in amount of elemental iron supplied; enteric-coated= decreased absorption as iron not released until after leaves small intestine [ferrous fumarate, ferrous gluconate, ferrous sulfate]
- gastric irritation, constipation
Hematinic Drugs
-Vitamin B12
- Absorption dependent of:
- Absorbed from:
- No dose-related _______
- Water-soluble vitamin; synthesized by bacteria; present in animal foods (vegetarians beware)
- Absorption dependent on secretion of intrinsic factor from gastric parietal calls [cyanocobalamin; hydroxocobalamin]
- Absorbed from terminal ileum into bloodstream
- No dose-related adverse reactions
Hematinic Drugs
- Folic Acid absorbed in:
- Evaluate basis of megaloblastic anemia ______ to instituting therapy as may be _______ deficient
- absorbed in duodenum
- prior, Vitamin B12
Hematinic Drugs
- Erythropoietin Agents:
- Erythropoietin normally formed in ______ in response to ______ (reduced oxygen) and ______
- Adverse Effect:
- boost erythropoietin production, stimulating RBC production in bone marrow
- kidneys, hypoxia and anemia
- hypertension most common
Anti-coagulant Drugs
-Reduce ability of blood to?
Classes
-Heparin:
- Oral anti-coagulants:
- Anti-platelets:
- Thrombin inhibitors:
- Factor Xa inhibitors:
-clot
Heparin-prevents fibrin formation
Oral -alter ability of liver to synthesize Vitamin K [warafin]
Anti-platelets -interfere with platelet activity [aspirin, clopidogrel, dipyridamole, sylfinpyrazone, ticlopidine]
Thombin - block thrombin activity; act against formed clots [lepirudin, argatroban, bivalirudin]
-Xa- bind anti-thrombin III to neutralize factor Xa; for clot prevention in hip/knee replacement surgery [fondaparinux]
Blood coagulation:
- platelets circulating in blood activated to adhere to site of injury
-Release chemical mediators ➡ attracts more
platelets➡ ‘platelet plus’ formed - COAGULATION CASCADE (stimulated)
Pro-thrombin (factor II) ➡ Thrombin (factor IIa) ➡ Fibrinogen (Factor I) ➡ Fibrinogen (factor I) ➡ Fibrin (insoluble) ____Factor XIIIa) _________Fibrin (insoluble)
Blood Coagulation
-Heparin
- Activates anti-thrombin III, which inactivates various factors in coagulation cascade (Thrombin IIa and Factor XIII blocked off)
- New thrombi prevented from forming.
Blood Coagulation
-Oral Anti-Coagulants: Warfarin (coumarin)
- Alters ability of liver to make Vitamin K
- Inactivates varous factors in coagulation cascade dependent on Vitamin K as co-factor
- Monitor usage with INR (International Normalized Ratio) to decrease risk of bleeding.
- (Drug initally used as rodenticide (rat Poison))
-No Pro-thrombin factor II
Blood Coagulation
-Anti-platelets: Aspirin
- Interferes with aility of platelets to aggregate at site of injury
- platelet plug not formed
- Permanent effect for entire life of platelet (3-7 days)
Blood Coagulation
-Thrombin Inhibitors:
- Convert plasminogen to plasmin, which cleaves fibrin ➡ thrombi lysed
- Clot dissolution dependent on how early therapy initiated
Blood Coagulation
-Factor Xa Inhibitors:
- binds anti-thrombin III, further neutralizing Factor Xa in coagulation cascade
- Clot formation inhibited
- Fondaparinux: only one authorized in U.S.
Adverse Effects of Anti-coag drugs
-primary adverse reaction to oral anti-coagulant therapy is bleeding, commonly in GI tract
Thrombolytic Drugs
-Dissolve:
-Activate:
- dissolve pre-existing clots/thrombi [alteplase, streptokinase, reteplase, tenecteplase, urokinase]
- Activate plasminogen (precursor to plasmin, which dissolves fibrin clots)
