Hemostasis Drugs

Question 1

Hemostasis

Answer 1

Process that halts bleeding after injury to a blood vessel
1.Formation of a platelet plug
2.Production of fibrin

Question 2

Anticoagulants

Answer 2

•Inhibit the action or formation of clotting factors
•Prevent clot formation
•Clotting cascade: results in fibrin which forms clots
•Anticoagulants are used prophylactically to prevent thrombus (clot formation), and embolus (dislodged clot)
•Have NO EFFECT on existing clots

Heparin
Low-molecular-weight heparins
Warfarin
Direct-Acting Oral Anticoagulants (DOACs)

Question 3

Antiplatelet drugs

Answer 3

Inhibit platelet aggregation
Prevent platelet plugs

Question 4

Thrombolytic Drugs

Answer 4

Lyse (break down) existing clots

Question 5

Hemostatic drugs

Answer 5

Promote blood coagulation

Question 6

Heparin

Answer 6

Anticoagulants

Heparin: indirectly inhibits activity of Thrombin II
•+ other factors in intrinsic pathway

•Monitored by activated partial thromboplastin times (aPPT)
•aPPT measure of intrinsic pathways and need to be 1.5-2.5 x greater than control

•Parenteral - IV or SC
•Anticoagulant effects reversed by protamine sulfate

Question 7

low-molecular-weight heparins

Answer 7

•Anticoagulant
•More predictable anticoagulant response
•Do not require frequent laboratory monitoring
•Often given at home: SC in abdomen only
•indirectly inhibits Factor X only
•Drug: Enoxaparin

Question 8

Warfarin

Answer 8

•Anticoagulant
•Oral only
•Vitamin K agonist (vit K essential for production of clotting factor)

•prothrombin time (PT) and INR (international normalization ratio) monitored by clotting test lab
•Normal INR range: 2–3x control
-Some need to be 2.5-3.5x
•Vitamin K can be given if excessive PT/INR
•Warfarin STRONGLY contraindicated in pregnancy

Question 9

Anticoagulant client education

Answer 9

•Keep intake of vitamin K constant (tomatoes, dark leafy green vegetables)
•Medical alert bracelet

Question 10

Nursing indications: warfarin

Answer 10

•Warfarin may be started while the client is still on heparins
•until prothrombin times/INR indicate adequate anticoagulation

Question 11

Direct-Acting Oral Anticoagulants (DOACs)

Answer 11

•Anticoagulants

Danigatran
•Direct thrombin inhibitor
•PO administration
-Rapid onset, fixed doses, no blood test, few drug interactions, low risk of bleeds

Rivaroxaban
•Direct factor Xa inhibitor
•PO administration
•Similar advantages as dabigatran

Question 12

Antiplatelet Drugs

Answer 12

•Prevent platelet activation
•Reduce risk of MI, stroke

ASA
•81 mg EC
•Irreversible inhibition of COX in platelets

Clopidogrel
•Irreversible ADP receptor blocker

•Aspirin + clopidogrel combination = additive antiplatelet activity but increased bleeding potential

Question 13

Thrombolytic Agents
(fibrinolytic agents)

Answer 13

•Drugs that break down preformed clots

•Activate plasminogen and convert it to plasmin, which can digest fibrin

Recombinant tissue plasminogen activator (tPA)
•DRUG: Alteplase

INDICATIONS:
Acute MI, Arterial thrombolysis, DVT, occlusion of shunts or catheters, pulmonary embolus

ADVERSE:
-Bleeds
-Dysrhythmias

Question 14

Antifibrinolytic Agents

Answer 14

•drugs that act by inhibiting the process that dissolves clots, thereby reducing bleeding.
•Promote clot formation and/or clot maintenance

Aminocaproic acid
•Blocks plasminogen activation

Never used in DIC (disseminated intravascular coagulation)