Heme Drugs

Question 1

Warfarin MOA

Answer 1

inhibits epoxide reductase (reduces Vit K to activate Factors II, VII, IX, X & Proteins S & C) (inhibits pro-coagulation factors)

Question 2

Heparin MOA

Answer 2

activates antithrombin (which inhibits activated forms of procoagulation factors: Factor IIa (thrombin), VIIa, IXa, Xa, XIa, XIIa) (activates anti-coagulation pathway)

Question 3

tPA

Answer 3

thrombolytic catalyses reaction of plasminogen to plasmin which cleaves the fibrin mesh into fibrin degradation pathways.

Question 4

Aspirin

Answer 4

Inhibits cycloxygenase (enzyme that transforms arachadonic acid to thromboxane A2) decreases aggregation of platelets

Question 5

Clopidogrel & Ticlopidine

Answer 5

inhibit ADP-receptor-induced expression of GpIIb/IIIa (decrease GpIIb/IIIa expression on platelet surface) decreases aggregation of platelets/ linking

Question 6

Abciximab

Answer 6

inhibits GpIIb/IIIa directly cannot bind fibrinogen and aggregate platelets

Question 7

Hereditary Spherocytosis

Answer 7

Splenectomy is curative (post-splenectomy will have howell-jolly bodies)

Question 8

Paroxysmal Nocturnal Hemoglobinuria

Answer 8

Eculizumab

Question 9

Sickle Cell Disease

Answer 9

Hydroxyurea (increases HbF) bone marrow transplant

Question 10

Lead poisoning

Answer 10

Dimercaprol EDTA

Question 11

Acute intermittent porphyria

Answer 11

glucose + heme (inhibits ALA synthase)

Question 12

Sideroblastic anemia

Answer 12

pyroxidine (B3) (co-factor for D-ALA synthase– which is deficient in hereditary (XLR) sideroblastic anemia

Question 13

von Willebrand’s disease

Answer 13

DDAVP (desmopressin) releases vWF protein from endothelium

Question 14

Packed RBCs trasnfusion effect

Answer 14

inc Hb & O2 carrying capacity

Question 15

Packed RBC transfusion indication

Answer 15

severe anemia acute blood loss

Question 16

Platelet transfusion effect

Answer 16

inc platelet count by ~5,000/mm3/unit

Question 17

Platelet transfusion indication

Answer 17

significant bleeding (stop) thrombocytopenia qualitative platelet defect

Question 18

Fresh frozen plasma transfusion effect

Answer 18

increases coagulation factor levels

Question 19

Fresh frozen plasma transfusion indication

Answer 19

DIC warfarin OD cirrhosis

Question 20

Cryoprecipitate transfusion effect

Answer 20

increases fibrinogen, fibronectin & factors VIII, XIII & vWF

Question 21

Cryoprecipitate transfusion indication

Answer 21

coagulation factor deficiencies– esp involving fibrinogen & factor VIII (hemophilia A)