Chapter 26 Coagulation Modifier Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc

Chapter 26

Coagulation Modifier Drugs

Copyright © 2014 by Mosby, an imprint of Elsevier Inc.

General term for any process that stops bleeding

Coagulation is hemostasis that occurs due to physiologic clotting of blood

Complex relationship between substances that promote clot formation and either inhibit coagulation or dissolve a formed clot

Hemostasis

Copyright © 2014 by Mosby, an imprint of Elsevier Inc. 2

“Cascade” Each activated factor serves as a catalyst that

amplifies the next reaction Result is fibrin, a clot-forming substance Intrinsic pathway and extrinsic pathway

Coagulation System





Anticoagulants Inhibit the action or formation of clotting factors Prevent clot formation

Antiplatelet drugs Inhibit platelet aggregation Prevent platelet plugs

Coagulation Modifier Drugs


Hemorheologic drugs Alter platelet function

Thrombolytic drugs Lyse (break down) existing clots

Antifibrinolytic or hemostatic Promote blood coagulation

Coagulation Modifier Drugs (cont’d)


Also known as antithrombotic drugs Have no direct effect on a blood clot that is

already formed Used prophylactically to prevent

Clot formation (thrombus) An embolus (dislodged clot)

Anticoagulants


warfarin sodium (Coumadin) enoxaparin (Lovenox) heparin dabigatran (Pradaxa) fondaparinux (Arixtra) argatroban (Argatroban)

Anticoagulants (cont’d)


Vary, depending on drug Work on different points of the clotting cascade Do not lyse existing clots

Anticoagulants:Mechanism of Action


Used to prevent clot formation in certain settings where clot formation is likely Myocardial infarction Unstable angina Atrial fibrillation Indwelling devices, such as mechanical heart valves Major orthopedic surgery

Anticoagulants: Indications


Bleeding Risk increases with increased dosages May be localized or systemic

May also cause: Heparin-induced thrombocytopenia (HIT) Nausea, vomiting, abdominal cramps,

thrombocytopenia, others

Anticoagulants: Adverse Effects


Heparin Monitored by activated partial thromboplastin times

(aPTTs) Parenteral Short half-life (1 to 2 hours) Effects reversed by protamine sulfate



Classroom Response Question

A patient is receiving an IV infusion of heparin and was started on warfarin therapy the night before. Which statement is most correct?

A.The patient is receiving a double dose of anticoagulants.

B.The heparin therapy was ineffective, so the warfarin was started.

C.The heparin provides anticoagulation until therapeutic levels of warfarin are reached.

D.The heparin and warfarin work together synergistically to provide anticoagulation.


Low–molecular-weight heparins enoxaparin (Lovenox) and dalteparin (Fragmin) More predictable anticoagulant response Do not require laboratory monitoring Given subcutaneously Do NOT rub after administration



warfarin sodium (Coumadin) Given orally only Monitored by prothrombin time and INR (PT-INR) Vitamin K can be given if toxicity occurs



Prevent platelet adhesion aspirin clopidogrel (Plavix)

• prasugrel (Effient) and ticagrelor (BRILINTA) are similar to clopidogrel

tirofiban (Aggrastat), eptifibatide (Integrilin), abciximab (ReoPro)

• GP IIb/IIIa inhibitors

Antiplatelet Drugs




Antithrombotic effects Reduce risk of fatal and nonfatal strokes Acute unstable angina and MI

Adverse effects Vary according to drug

Antiplatelet Drugs: Indications


Drugs that break down, or lyse, preformed clots Older drugs

streptokinase and urokinase Current drugs

anistreplase (Eminase) alteplase (Activase) reteplase (Retavase) tenecteplase (TNKase)

Thrombolytic Drugs


Activate the fibrinolytic system to break down the clot in the blood vessel quickly

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

Reestablish blood flow to the heart muscle via coronary arteries, preventing tissue destruction

Thrombolytic Drugs: Mechanism of Action


Acute MI Arterial thrombolysis DVT Occlusion of shunts or catheters Pulmonary embolus Acute ischemic stroke

Thrombolytic Drugs: Indications


Bleeding Internal Intracranial Superficial

Other effects Nausea, vomiting, hypotension, anaphylactoid

reactions Cardiac dysrhythmias; can be dangerous

Thrombolytic Drugs: Adverse Effects



A patient is receiving an intravenous infusion of a thrombolytic drug during treatment for an acute MI. The nurse notices that there is a slight amount of bleeding from the antecubital area where venous lab work was drawn. What will the nurse do first?

A.Monitor the site for further bleeding.

B.Apply pressure to the site with a gauze pad.

C.Slow the rate of infusion of the thrombolytic drug.

D.Stop the infusion of the thrombolytic drug.


Prevent the lysis of fibrin Result in promoting clot formation Used for prevention and treatment of excessive

bleeding resulting from hyperfibrinolysis or surgical complications

Treatment of hemophilia or von Willebrand’s disease

Antifibrinolytic Drugs


aminocaproic acid (Amicar) desmopressin (DDAVP)

Similar to ADH Also used in the treatment of diabetes insipidus

Antifibrinolytic Drugs (cont’d)


Uncommon and mild Rare reports of thrombotic events Others include:

Dysrhythmia, orthostatic hypotension, bradycardia, headache, dizziness, fatigue, nausea, vomiting, abdominal cramps, diarrhea, others

Antifibrinolytic Drugs:Adverse Effects


Assess: Patient history, medication history, allergies Contraindications Baseline vital signs, laboratory values Potential drug interactions History of abnormal bleeding conditions

Nursing Implications


Intravenous doses are usually double-checked with another nurse

Ensure that subcutaneous doses are given subcutaneously, not IM

Subcutaneous doses should be given in areas of deep subcutaneous fat, and sites rotated

Heparin: Nursing Implications


Do not give subcutaneous doses within 2 inches of: The umbilicus, abdominal incisions, or open wounds,

scars, drainage tubes, stomas Do not aspirate subcutaneous injections or

massage injection site May cause hematoma formation

Heparin: Nursing Implications (cont’d)


IV doses may be given by bolus or IV infusions Anticoagulant effects seen immediately Laboratory values done daily to monitor

coagulation effects (aPTT) Protamine sulfate can be given as an antidote in

case of excessive anticoagulation

Heparin: Nursing Implications (cont’d)


Given subcutaneously in the abdomen Rotate injection sites Protamine sulfate can be given as an antidote in

case of excessive anticoagulation

LWMHs: Nursing Implications


May be started while the patient is still on heparin until PT-INR levels indicate adequate anticoagulation

Full therapeutic effect takes several days Monitor PT-INR regularly—keep follow-up

appointments Antidote is vitamin K

Warfarin (Coumadin):Nursing Implications



A 75-year-old man fell at home and hit his head against a table. His wife reports to their daughter that he does not have cuts or scratches, but there is a small lump on his upper scalp. She does not see any blood. He is taking warfarin and an antidysrhythmic as part of his treatment for chronic atrial fibrillation. What is the main concern at this time?

A. Pressure should be applied to the lump for 3 to 5 minutes.

B. He will need to take two doses of warfarin tonight to prevent blood clotting.

C. He needs to be examined for possible internal bleeding from the fall.

D. As long as there is no bleeding, there is no concern.


Many herbal products have potential interactions—increased bleeding may occur Capsicum pepper Garlic Ginger Ginkgo St. John’s wort Feverfew

Warfarin (Coumadin):Nursing Implications



A 72-year-old woman is taking an over-the-counter multivitamin that contains ginkgo. Her physician has recommended that she start taking low-dose aspirin therapy as part of her treatment for transient ischemic attacks (TIAs). The concern with taking these two drugs together is:

A.increased risk of gastric ulcer.

B.decreased action of the aspirin because of the interaction with the ginkgo.

C.increased risk of bleeding because of the ginkgo.

D.antagonism of the action of the aspirin because of the multivitamins.


Education should include: Importance of regular laboratory testing Signs of abnormal bleeding Measures to prevent bruising, bleeding, or tissue

injury

Anticoagulants:Patient Education


Education should include (cont’d): Wearing a medical alert bracelet Avoiding foods high in vitamin K (tomatoes, dark leafy

green vegetables) Consulting physician before taking other drugs or

over-the-counter products, including herbals

Anticoagulants:Patient Education (cont’d)


Concerns and teaching tips same as for anticoagulants

Drug-drug interactions Adverse reactions to report Monitoring for abnormal bleeding

Antiplatelet Drugs:Nursing Implications


Follow strict manufacturer’s guidelines for preparation and administration

Monitor IV sites for bleeding, redness, pain Monitor for bleeding from gums, mucous

membranes, nose, injection sites Observe for signs of internal bleeding

(decreased BP, restlessness, increased pulse)

Thrombolytic Drugs:Nursing Implications


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Chapter 26 Coagulation Modifier Drugs Copyright © 2014 by Mosby, an imprint of Elsevier Inc