Pharmacology: Anticoagulants and Antiplatelets Unit 6.2

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Questions and Answers

What is the primary action of aspirin and clopidogrel?

To increase blood coagulation.

To break down existing blood clots

To prevent platelet aggregation. (correct)

To prevent the formation of new blood clots.

Which of the following is NOT a use of warfarin?

Treatment of acute ischemic stroke. (correct)

Treatment of atrial fibrillation

Prevention of deep vein thrombosis (DVT)

Prevention of pulmonary embolism

What is the therapeutic range for INR when a patient is on warfarin therapy?

3-4

0.5-1.5

4-5

2-3 (correct)

Which of the following is an antidote for warfarin overdose?

Vitamin K Signup and view all the answers

Which of the following is a contraindication for the use of heparin?

Hemorrhagic stroke Signup and view all the answers

What is the route of administration for enoxaparin?

Subcutaneous (SubQ) Signup and view all the answers

Which of the following is NOT a side effect of alteplase, a thrombolytic drug?

Injection site irritation Signup and view all the answers

Which of the following is a contraindication for the use of alteplase?

Recent surgery Signup and view all the answers

What is the most important nursing intervention for a client who is on heparin therapy?

Monitoring for signs of bleeding Signup and view all the answers

Which of the following medications is a low-molecular-weight heparin (LMWH)?

Enoxaparin Signup and view all the answers

Which of these is the classification for clopidogrel?

Antiplatelet Signup and view all the answers

A client is recovering from surgery to replace her right hip. Which medication would the nurse anticipate administering to prevent deep vein thrombosis?

Low-molecular-weight heparin Signup and view all the answers

Which information is essential to include in a patient's teaching about warfarin therapy?

Follow up with laboratory tests such as PT or INR to regulate warfarin dose Signup and view all the answers

A client is on heparin therapy secondary to deep vein thromboses. Which medication should the nurse have on hand as an antidote?

Protamine sulfate Signup and view all the answers

Four clients are considered as potential candidates for thrombolytic therapy. Which client is most likely to receive thrombolytic therapy?

The client who recently used acetaminophen Signup and view all the answers

A client arrived in the emergency department 2 hours after an acute ischemic stroke and received an intravenous injection of alteplase. What is most important for the nurse to monitor? (Select all that apply)

Allergic reactions Signup and view all the answers

The client develops deep vein thrombosis. Which medication would the nurse anticipate administering?

Intravenous heparin Signup and view all the answers

The client is being discharged home on warfarin therapy. Which information should the nurse include in the teaching?

International normalized ratio (INR) results should be between 2 and 3 Signup and view all the answers

Study Notes

Anticoagulants, Antiplatelets, and Thrombolytics

Anticoagulants prevent clot formation.
Antiplatelets prevent platelet aggregation.
Thrombolytics dissolve existing clots.

Thrombus Formation - Pathophysiology

Clots form in arteries or veins.
Decreased circulation, vessel wall platelet aggregation, and blood coagulation cause clots.
Arterial clots involve platelets.
Fibrin formation traps red blood cells (RBCs) in clots.
Venous clots involve platelet aggregation and fibrin attaching to RBCs.

Drugs Used to Maintain or Restore Circulation

Antiplatelets: aspirin, clopidogrel
Anticoagulants: warfarin, heparin, enoxaparin
Thrombolytics: alteplase

Antiplatelet Drugs - Aspirin

Effective and inexpensive for suppressing platelet aggregation.
Low-dose therapy.
Inhibits platelet aggregation by inhibiting COX 1.
Use: Prevention of myocardial infarction (MI) and stroke.

Antiplatelets - Clopidogrel Bisulfate

Action: Suppresses platelet aggregation.
Used to prevent thrombosis in arteries, prevent myocardial infarction or stroke (especially in clients with a family history), prevent repeat myocardial infarction or stroke, and prevent stroke from transient ischemic attacks.

Side Effects/Adverse Reactions - Clopidogrel Bisulfate

Abdominal pain
Bleeding
Hypotension

Contraindications - Clopidogrel Bisulfate

Bleeding
Peptic ulcer
Liver disease
Renal disease

Interactions - Clopidogrel Bisulfate

Other drugs that cause bleeding (e.g., 5 G's: ginger, garlic, ginseng, ginkgo biloba, green tea)

Oral Anticoagulants - Warfarin

Action: Inhibits hepatic synthesis of vitamin K, impacting clotting factors II, VII, IX, and X.
Use: Prevents and treats blood clotting, used for treatment and prevention of deep vein thrombosis (DVT), pulmonary embolism, and stroke.
Monitoring: PT and INR (2-3)

Side Effects/Adverse Reactions - Warfarin

Gastrointestinal (GI) upset
Bleeding

Vitamin K

Antidote for warfarin overdose.
Effective 24-48 hours after administration.
For acute bleeding, fresh frozen plasma or platelets are administered.

Contraindications - Warfarin

Blood dyscrasias
Alcoholism
Head trauma
Diabetes mellitus

Interactions - Warfarin

Other drugs/herbs causing bleeding.
Medications increasing warfarin effect.
Maintaining consistent vitamin K food intake.

Oral Anticoagulants - Apixaban

Action: Selectively blocks clotting factor Xa to prevent clot formation.
Use: Prevents and treats DVT and PE, preventing stroke and atrial fibrillation.
Monitoring: Does not require routine coagulation monitoring.

Side Effects/Adverse Reactions - Apixaban

Bleeding
Hypotension

Contraindications - Apixaban

Clients weighing less than 50 kg (increased risk of bleeding)

Interactions - Apixaban

Other drugs/herbs causing bleeding.

Anticoagulants - Heparin

Action: Inhibits thrombin, fibrinogen-to-fibrin conversion, and clot formation.
Use: Prevents or treats venous thrombosis.
Administration: Subcutaneous or intravenous.
Monitoring: Frequent lab monitoring (PTT 1.5-2.5 times normal, aPTT 1.5-2.5 times normal).

Side Effects/Adverse Reactions - Heparin

Bleeding
Injection site irritation

Contraindications - Heparin

Hemorrhagic stroke
Bleeding issues
Use caution in clients with peptic ulcer disease
Interactions: Other drugs/herbs causing bleeding.

Anticoagulants - Enoxaparin

Type: Low-molecular-weight heparin (LMWH).
Action: Inactivates factor Xa.
Use: Prevent DVT and PE after orthopedic or abdominal surgery.
Precautions: Do not take aspirin concurrently or other drugs causing bleeding,
Administration: Subcutaneous, once or twice daily.

Thrombolytics - Alteplase

Action: Converts plasminogen to plasmin, degrading fibrin and other clotting factors, dissolving clots.
Uses: Dissolves clots following acute MI, pulmonary embolism, ischemic stroke, and DVT; all end in -ase.

Side Effects/Adverse Reactions - Alteplase

Anaphylaxis
Hemorrhage

Contraindications - Alteplase

Bleeding
Recent surgery/trauma
Severe liver dysfunction
Head trauma
Interactions: Other drugs/herbs causing bleeding (NSAIDs)

Nursing Process - Anticoagulants - Assessment

Baseline vital signs
Complete blood count (CBC), PT, INR, and PTT.
Medical history
Recent surgeries/trauma
Time of event onset.
History of blood thinners (including ibuprofen) and other drugs causing bleeding
For thrombolytics, focus on recent surgeries/trauma, time of event onset.

Interventions - Anticoagulants

Monitor vital signs.
Monitor lab values (CBC, PT/INR for warfarin, PTT for heparin, all for alteplase).
Monitor for bleeding; Use soft toothbrush, electric razor, etc.
Have antidote available (heparin, warfarin).
Monitor for allergic reactions.
Avoid unnecessary venipunctures.

Teaching - Anticoagulants

Signs/symptoms of bleeding to report.
Use soft toothbrush, electric razor.
Inform dentists about medications.
Medic alert bracelet.
Stop smoking.
Avoid NSAIDs and other drugs, herbal products, that cause bleeding.
Maintain consistent vitamin K intake for warfarin diet.

Practice Questions (and answers are implied from provided text)

Detailed answers to all practice questions are provided in the document..

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Description

Explore the crucial roles of anticoagulants, antiplatelets, and thrombolytics in preventing and treating thrombus formation. This quiz covers the mechanisms, commonly used drugs, and their applications in maintaining blood circulation.