Hematology Drugs

Question 1

Mechanism of heparin

Answer 1

activator of antithrombin
decreases thrombin and factor Xa
short half-life

Question 2

Use of heparin

Answer 2

immediate anticogaulation for PE
acute coronary syndrome
MI
deep venous thrombosis (DVT)

Question 3

Can heparin be used during pregnancy?

Answer 3

YES

Question 4

Which will change with heparin use, PT or PTT?

Answer 4

PTT needs to be monitored

Question 5

Toxicity of heparin

Answer 5

bleeding
thrombocytopenia (HIT)
osteoporosis
drug-drug interactions

Question 6

What is the heparin antidote?

Answer 6

protamine sulfate that has + charge that will bind - charged heparin

Question 7

What are the low molecular weight heparins?

Answer 7

enoxaparin, dalteparin, and fondaparinux

Question 8

Benefit of LMWH?

Answer 8

act more on factor Xa
have better bioavailability
2-4 times longer half-life
can be administered subQ
need less laboratory monitoring
NOT easily reversible

Question 9

What is HIT?

Answer 9

heparin induced thrombocytopenia

Question 10

What is the mechanism of HIT?

Answer 10

development of IgG antibodies against heparin-bound platelet factor 4 (PF4)
antibody-heparin-PF4 complex activates platelets –> thrombosis and thrombocytopenia

Question 11

Mechanism of argatroban, bivalirudin and dabigatran?

Answer 11

inhibit thrombin directly

Question 12

Use of argatroban, bivalirudin and dabigatran?

Answer 12

alternative to heparin for anticoagulating patients with HIT

Question 13

Mechanism of warfarin

Answer 13

interferes with gamma-carboxylation of vitamin K-dependent clotting factors and protein C and S by blocking vitamin K epoxide reductase

Question 14

What are the vitamin K dependent clotting factors?

Answer 14

II, VII, IX, X (plus protein C and S inhibited)

Question 15

Can have polymorphism to warfarin response?

Answer 15

YES via the VKORC1 gene which is K epoxide reductase complex

Question 16

Labs to monitor warfarin use?

Answer 16

extrinsic pathway so monitor PT (sooner) and INR

also affects intrinsic and PTT

Question 17

Use of warfarin

Answer 17

chronic anticoagulation

Question 18

Can you use warfarin in pregnant women?

Answer 18

NO - crosses the placenta

Question 19

Toxicity of warfarin

Answer 19

bleeding, teratogenic, skin/tissue necrosis (believed to be due to small vessel microthromboses), drug-drug interactions

Question 20

Warfarin and protein C and S

Answer 20

protein C and S have shorter half-lives than clotting factors II, VII, IX, X resulting in early transient hypercoagulability with warfarin use

Question 21

Antidote to warfarin overdose? rapid reversal?

Answer 21

vitamin K; fresh frozen plasma

Question 22

what is Heparin “bridging”?

Answer 22

heparin frequently used when starting warfarin because it only inhibits the new production of clotting factors not those that already exist

initial heparin with warfarin decreases risk of recurrent venous thromboembolism and skin/tissue necrosis

Question 23

Name the direct factor Xa inhibitors

Answer 23

apixaban and rivaroxaban

Question 24

Mech of the direct Xa inhibitors

Answer 24

bind to and directly inhibit factor Xa

Question 25

Use of direct Xa inhibitors

Answer 25

tx and prophylaxis for DVT and PE (rivaroxiban) | stroke prophylaxis in patients with atrial fibrillation

Question 26

Do you need to monitor labs with direct Xa inhibitors?

Answer 26

not usually because oral agents don't require coagulation monitoring

Question 27

Toxicity of direct Xa inhibitors

Answer 27

bleeding (no reversal agent available)

Question 28

Name the thrombolytics

Answer 28

alteplase, reteplase, streptokinase, tenecteplase

Question 29

Mechanism of thrombolytics

Answer 29

directly or indirectly aid in conversion of plasminogen to plasmin which cleaves thrombin and fibrin clots

Question 30

Lab changes with thrombolytics

Answer 30

increased PT and PTT, no change in platelet count

Question 31

Use of thrombolytics

Answer 31

early MI (within first 6 hrs) early sichemic stroke direct thrombolysis of severe PE

Question 32

Toxicity of thrombolytics

Answer 32

bleeding

Question 33

Contraindication of thrombolytics

Answer 33

in patients with active bleeding, history of intracranial bleeding, recent surgery, known bleeding diatheses, or severe hypertension

Question 34

Antidote to thrombolytics

Answer 34

aminocaproic acid, an inhibitor of fibrinolysis | fresh frozen plasma and cryoprecipitate can also be used to correct factor deficiencies

Question 35

Mechanism of aspirin

Answer 35

irreversibly inhibits COX1 and COX2 enzyme by covalent acetylation platelets cannot synthesize new enzyme, so effect lasts until new platelets are produced

Question 36

Lab changes with aspirin

Answer 36

increased bleeding time decreased TXA2 and prostaglandins no effect on PT or PTT

Question 37

Use of aspirin

Answer 37

antipyrectic, analgesic, anti-inflammatory, antiplatelet (decrease aggregation)

Question 38

Toxicity of aspirin

Answer 38

gastric ulceration, tinnitus (CN VIII) | chronic: acute renal failure, intersitial nephritis, upper GI bleeding

Question 39

What is Reye syndrome?

Answer 39

precipitated by aspirin use in children with viral infection

Question 40

Overdose of aspirin presentation?

Answer 40

early presents with hyperventilation and respiratory alkalosis but transitions to mixed metabolic acidosis-respiratory alkalosis

Question 41

Name the ADP receptor inhibitors

Answer 41

clopidogrel, prasugrel, ticagrelor (reversible), ticlodipine

Question 42

Mechanism of ADP receptor inhibitors

Answer 42

inhibit platelet aggregation by irreversibly blocking ADP receptors prevent expression of glycoproteins IIb/IIIa on platelet surface and prevents platelet-platelet interactions

Question 43

Use of ADP receptor inhibitors

Answer 43

acute coronary syndrome coronary stenting decreased incidence or recurrence of thrombotic stroke

Question 44

Toxicity of ADP receptor inhibitors | Specifically ticlodipine? Presentation?

Answer 44

neutropenia (ticlodipine) - presents with fever and mouth ulcers TTP may be seen

Question 45

Name the 2 phosphodiesterase III inhibitors

Answer 45

cilostazol, dipyridamole

Question 46

Mech of PDE 3 inhibitors

Answer 46

inhibit enzyme leading to increase cAMP in platelets resulting in inhibition of platelet aggregation VASODILATION as well

Question 47

Use of PDE 3 inhibitors

Answer 47

intermitten claudication coronary vasodilation prevention of stroke or TIAs (combined with aspirin) angina prophylaxis

Question 48

Toxicity of PDE 3 inhibitors

Answer 48

nasuea, headache, facial flushing, hypotension, abdominal pain

Question 49

Name the GP IIb/IIIa inhibitors

Answer 49

abciximab, eptifibatide, tirofiban

Question 50

Mechanism of GP IIb/IIIa inhibitors

Answer 50

bind to glycoprotein receptor IIb/IIIa on activated platelets and prevent aggregation

Question 51

Use of GP IIb/IIIa inhibitors

Answer 51

unstable angina | percutaneous transluminal coronary angioplasty (PCI)

Question 52

Toxicity of GP IIb/IIIa inhibitors

Answer 52

bleeding | thrombocytopenia