Drugs Affecting Blood

Question 1

Anticoagulants:
1-
2-
3-

Answer 1

Heparin
Low molecular heparins
Vitamin K antagonists

Question 2

Role of anticoagulants
1-
2-

Answer 2

Inhibit the action of coagulation factors
Interfere with the synthesis of coagulation factors

Question 3

Thrombin inhibtors
1-
2-

Answer 3

Heparin
LMWH

Question 4

Unfractionated heparin mixture of ——
Strongly —–

Answer 4

Glycosaminoglycans (glucosamine and glucurunic acid)
Strongly acidic ( sulfate and sulfate group)

Question 5

LMWH:——-
Size:—–
Form—-

Answer 5

Enoxaparin
1/3 size of unfrationated heparin
Chemical or enzymatic depolymerization of unfractionated heparin
(Replacin heparin)

Question 6

Effect of heparin vs LMWH
Availability of heparin vs LMWH

Answer 6

Hep: minutes after IV vs LMWH 4 hrs
Heparin binds to many proteins that neutralize its activity thereby causing resistance to the drug

Question 7

T or F
LMWH is taken up by the monocyte/macrophage system and undergo further depolymerization

Answer 7

False
Heparin and not LMWH

Question 8

Excretion
Half life of each

Answer 8

Both excreted to urine (renal insufficiency prolongs half life)

Heparin 1.5 hrs
LMWH 3-7 hrs

Question 9

T or F
Heparin doesn’t cross the placenta while LMWH do.

Answer 9

False
Both don’t

Question 10

Bioavailability of heparin vs LMWH
Major adverse effect of each
Setting for therapy

Answer 10

20% heparin 90% LMWH
Frequent bleeding for heparin while less frequent for LmWH
Heparin is always taken in hospital while LMWH in hospital or outpatient

Question 11

Mech of action of both:

Answer 11

Binding and activating of anti thrombin III by its pentasaccharide sequence
Rapid inactivation of coagulation factors
Heparin inhibit thrombin and cofactor Xa
LMWH inhibit Xa

Question 12

T or F
Antithrombin is a serine protease

Answer 12

T

Question 13

Adverse effects of both:
1-
2-
3

Answer 13

1-Bleeding: excessive may be managed by ceasing of the drug or by treating with protamine sulfate
2-Thrombosis: chronic or intermittnet adm lead to reduction in antithrombin III (low dose should be used)
3-Thrombocytopenia I: non immunologic (heparin-induced thrombocytopenia)
Thrombocytopenia II:immunoallergic

Question 14

T or F
Thrombocytopenia I occur usually from 5 to 14 days

Answer 14

False
I the first 5 days
While II from 5 to 14 (replace it by other anticoagulant)

Question 15

Contraindications of heparin nad LMWH:
1-
2-
3-

Answer 15

Hypersensitivity
Bleeding disorders
Having a recent brain or eye surgery

Question 16

Therapeutic uses:
1-
2-
3-

Answer 16

Acute deep vein thrombosis and pulmonary embolism
Prophylaxis to prevent venous thrombosis in oatients undergoing elective surgery and those in acute MI
Extracorporeal devices (dialysis machines)

Question 17

Oral anticoagulats:
Anti-thrombin:
Anti-Xa:
1-
2-

Answer 17

Dahigatran etexilate:praxada

1- Rivaroxaban
2- Apixaban

Question 18

Uses of oral anti-Xa

Answer 18

For stroke prevention in atrial fibrillation

Question 19

T or F
Dabigatran etexilate is a prodrug
Used instead of enoxaparin for thrombophylaxis in orthopedic surgeries

Answer 19

T
Dabigatran is the active moiety

Question 20

Which factors need vitamin K in there synthesis?

Answer 20

II ,VII, IX ,X
They are carboxylated on their glutamic acid

Question 21

Warfarin a vitamin K antagonist results in ———, with effects observed at—— but peak effect can be delayed to —

Answer 21

Production of clotting factors with diminished activity (10-40% of normal)
8-12 hr
72-96 hrs

Question 22

Warfarin
Bioavailability:
Binding to protein:
Can be displaced by:
Half life:
Fate:

Answer 22

100%
97-99 (prevents its diffusion to CSF,urine and breast milk)
Sulfonamides
40 hrs vary among individu
Catalyzed by P450
Conjugated to glucuronic acid
Urine or stool

Question 23

Therapeutic uses of warfarin:
1-
2-
3-

Answer 23

Prevent recurrence of DVT or PE
Venous thromboembolism during orthopedic surgery
Prophylactically(acute MI,prosthetic heart valves or chronic atrial fibri)

Question 24

Adverse effects of warfarin
1-
2-
3-

Answer 24

1-bleeding disorders (INR is important)
2-minir bleeding may be treated by withrawal of the drug andmi of oral viramin K
3-severe bleeding in IV
(Whole blood, frozen plasma or plasma concentrates must be used in this case)

Question 25

Drug drug interactions

Answer 25

On slide 35

Question 26

Comtraindications

Answer 26

Because warfarin can pass through placenta it should be never given to a pregnant woman because it causes teratogenic effects or abortion as well as birth defects

Question 27

Platelet aggregation inhibitors classes 1- 2- 3-

Answer 27

1-COX-1 inhibitors 2-ADP receptors antagonists 3- GPIIbIIIa receptor antagonist

Question 28

Cox1 inhibitor named ---- inhibits ----- by ------ of ----- The effect is (rapid/slow)----- Suppression of platelet aggregation last for ----

Answer 28

Aspirin Thromboxane A2 Irrevesible acetylation of serine COX Rapid The life of platelet (7-10 days)

Question 29

Therapeutic uses of aspirin: 1- 2- Recommended does:

Answer 29

Prophylactic tx of transient cerebral ischemia To reduce the incidence of recurrent myocardial infarction 81-325 mg

Question 30

Adverse events of aspirin: 1- 2-

Answer 30

1-bleeding time is prolonged by aspirin tx causing complications that include and increased incidence of hemorrhagic stroke as well as gastrontestinal bleeding especially at higher doses of yhe drug 2-could be used in combination with other drugs having anticlotting properties (heparin) or clopidogrel

Question 31

ADP receptors antagonists: Names 1- 2- 3-

Answer 31

Dipyridamole Ticlopidine Clopidogrel

Question 32

Ticlopidine and clopidogrel mech of action: Class type:

Answer 32

Inhibit binding of ADP irrevesibly Thus inhibit the activation of GPIIb/IIIa required for platelet to bind to fibrinogen and to each other Thienopyridines

Question 33

Ticlopidine uses: 1- 2-

Answer 33

1-transient ischemic attacks and strokes for patients with prior cerebral thrombotic event 2-as adjunct therapy with aspirin following coronary stent implantation to decrease the incidence of stent thrombosis

Question 34

Adverse effects of ticlopidine

Answer 34

Neutropenia Agranulocytosis Thrombotic thrombocytopenia purpura Aplastic anemia (Reversed)

Question 35

Clopidogrel uses: 1- 2_

Answer 35

1-Prevention of atherosclerotic events following infarction,stroke or established peripheral atterial disease 2-prophylaxis of thrombotic events in acute coronary syndrome (unstable angina MI)

Question 36

T or F Ticlopidine is preffered in ischemic heart disease

Answer 36

False Reversed

Question 37

T or F Clopidogrel has a better overall side effect profile

Answer 37

T Lower incidence of neutropenia in clopidogrel

Question 38

Dipyridamole uses: 1- 2- Mode of action:

Answer 38

1-coronary vasodilator (prophylactically to treat angina pectoris) 2- in combination with aspirin or warfarin (ineffective when used alone) Increase intracellular levels of cAMP by inhibiting phosphodiesterase resulting in decreased thromboxane A2 synthesis

Question 39

GP receptors antagonist names : 1- 2- 3-

Answer 39

1-abciximab 2-eptifibatide 3-tirofiban

Question 40

Abciximab Mode of action: Mode of administration; Uses: Persistance of effect: Adverse:

Answer 40

Monoclonal antibody directed against GP complex therefore blocking the fibrinogen binding (no agg) IV with heparin or aspirin Prevention of cardiac ischemic complication 24-48 hrs Potential bleeding

Question 41

Throbolytic agents: 1- 2- 3-

Answer 41

1-Streptokinase 2-Tissue plasminogen activator (alteplase) 3-urokinase

Question 42

Mode of action of Streptokinase Alteplase Urokinase

Answer 42

Systemic fibrinolysis Activates the conversion of plasminogen into plasmin thay hydrolyzes fibrin Enzyme synthesized in kidneys that transform plasminogen into plasmin

Question 43

T or F Alteplase acts systemitically to produce fibrinolysis

Answer 43

False acts more locally

Question 44

Therapeutic uses: 1- 2- 3-

Answer 44

1-DVT 2-serious pulmonary embolism 3-acute MI or peripheral arterial thrombosis