Hematology Drugs

Question 1

Heparin

Answer 1

MOA: activates antithrombin which lowers activity of thrombin & factor Xa
CU: IMMEDIATE ANTICOAG for PE, acute coronary syndrome, MI, DVT - follow PTT - short 1/2 life
SAFE IN PREGANT WOMEN (doesn’t cross placenta)
AE: bleeding, thrombocytopenia (HIT), osteoporosis, DDI

Question 2

Heparin’s Antidote

Answer 2

Protamine sulfate (positive charged molecule that binds negative charged heparin)

Question 3

LMW Heparins (Enoxaparin, Dalteparin) & Fondaparinux

Answer 3

Act more on factor Xa
longer 1/2 life
Given SubQ w/o lab monitoring BUT not easily reversed

Question 4

Heparin-Induced Thrombocytopenia (HIT)

Answer 4

IgG Ab’s form against heparin-bound platelet factor 4 (PF4)
Ab/Ag complex activates platelets - thrombosis & thrombocytopenia
Tx: Direct Thrombin Inhibitors

Question 5

Direct Thrombin inhibitors

Answer 5

Bivalirudin (=hirudin leech anticoagulant) & Argatroban
Thrombin = factor II = “Bi”
Inhibitor = “rude!” = -rudin

Question 6

Bivalirudin & Argatroban

Answer 6

MOA: direct thrombin inhibitor
CU: Venous thromboembolism, a-fib, HIT
AE: bleeding w/o reversal agent
Notes: no lab monitoring required

Question 7

Warfarin MOA

Answer 7

Inhibits y-carboxylation of Vit K dependent clotting factors (II, VII, IX, X & Protein C, S) = extrinsic pathway effects = increase PT
Polymorphisms in Vit K Epoxide Reductase complex gene (VKORC1) affect metabolism - need lower dose

Question 8

Warfarin CU

Answer 8

Chronic anticoagulation (prophylaxis for venous thromboembolism & stroke prevention in a-fib)
NOT SAFE IN PREGNANT WOMEN - crosses placenta
Follow PT/INR

Question 9

Warfarin AE’s

Answer 9

Bleeding, skin/tissue necrosis (w/in first days of large doses - microthromboses); teratogenic; DDI
Protein C & S - shorter half-lives = early transient hypercoagulability BRIDGE WITH HEPARIN (activates antithrombin)

Question 10

Warfarin Reversal

Answer 10

Rapid Reversal: fresh frozen PLASMA (has coag factors)

Long-term reversal: Vit K

Question 11

Direct Factor Xa inhibitors

Answer 11

Apixaban, rivaroxaban

Question 12

Apixaban, rivaroxaban

Answer 12

MOA: bind/inhibit Factor Xa
CU: Tx/prophylaxis DVT and PE (rivaroxaban); stroke prophylaxis in a-fib
Oral - no monitoring
AE: Bleeding W/O REVERSAL AGENTS

Question 13

Thrombolytics

Answer 13

Alteplase (tPA), reteplase, tenecteplase

Streptokinase!

Question 14

-teplase & streptokinase MOA

Answer 14

Convert plasminogen to plasmin which cleaves thrombin and fibrin clots (increases PT and PTT)
No change in platelet count

Question 15

Thrombolytics CU

Answer 15

Early MI, ischemic stroke, direct thrombolysis of severe PE

Question 16

Thrombolytics AE & Reversal

Answer 16

AE: Bleeding
CI’s: active bleeding, Hx of intracranial bleed, recent surgery, severe HTN
Toxicity Tx: Aminocaproic acid (fibrinolysis inhibitor)
Correct factor deficiencies w/fresh frozen plasma/cryoprecipitate.

Question 17

Clopidogrel, prasugrel, ticagrelor (reversible)

Ticlopidine

Answer 17

MOA: irrev blocks ADP R’s preventing expression of gp’s IIb/IIIa on platelet surface - inhibits platelet aggregation.
CU: acute coronary syndrome/coronary stenting; decrease thrombotic stroke occurrence.
AE: Neutropenia (ticlopidine); TTP

Question 18

Cilostazol, dipyridamole

Answer 18

Phosphodiesterase III inhibitor - increases cAMP in platelets inhibiting aggregation & causing vasodilation
CU: intermittent claudication, coronary vasodilation, angina prophylaxis
Combo w/aspirin for prevention of stroke/TIAs
AE: N, HA, flushing, hypoTN, abdominal pain

Question 19

Abciximab
Eptifibatide
Tirofiban

Answer 19

Glycoprotein IIb/IIIa inhibitors - prevent platelet aggregation
Abciximab (monoclonal Ab Fab fragments)
CU: unstable angina, percutaneous transluminal coronary angioplasty
AE: bleeding, thrombocytopenia