Coagulation Modifier Drugs

Coagulation Modifier Drugs
Chapter 26 Coagulation Modifier Drugs Copyright © 2017, Elsevier Inc. All rights reserved.

Copyright © 2017, Elsevier Inc. All rights reserved.
Hemostasis General term for any process that stops bleeding Coagulation is hemostasis that occurs because of the physiologic clotting of blood Complex relationship between substances that promote clot formation and either inhibit coagulation or dissolve a formed clot Thrombus: technical term for a blood clot Embolus: thrombus that moves through blood vessels Copyright © 2017, Elsevier Inc. All rights reserved.

Coagulation System “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 Copyright © 2017, Elsevier Inc. All rights reserved.

The fibrinolytic system.
Copyright © 2017, Elsevier Inc. All rights reserved.

Fibrinolytic System Initiates the breakdown of clots and serves to balance the clotting process Fibrinolysis: mechanism by which formed thrombi are lysed to prevent excessive clot formation and blood vessel blockage Copyright © 2017, Elsevier Inc. All rights reserved.

Fibrinolytic System (Cont.)
Fibrin in the clot binds to a circulating protein known as plasminogen. This binding converts plasminogen to plasmin. Plasmin is the enzymatic protein that eventually breaks down the fibrin thrombus into fibrin degradation products. This keeps the thrombus localized to prevent it from becoming an embolus. Copyright © 2017, Elsevier Inc. All rights reserved.

Hemophilia Rare genetic disorder Natural coagulation and hemostasis factors are limited or absent. Patients with hemophilia can bleed to death if coagulation factors are not given. Two types inhibit platelet aggregation Factor VII deficiency Factor VIII and/or factor IX deficiency Copyright © 2017, Elsevier Inc. All rights reserved.

Coagulation Modifier Drugs
Anticoagulants Inhibit the action or formation of clotting factors Prevent clot formation Antiplatelet drugs Inhibit platelet aggregation Prevent platelet plugs Copyright © 2017, Elsevier Inc. All rights reserved.

Coagulation Modifier Drugs (Cont.)
Hemorheologic drugs Alter platelet function without preventing the platelets from working Thrombolytic drugs Lyse (break down) existing clots Antifibrinolytic or hemostatic Promote blood coagulation Copyright © 2017, Elsevier Inc. All rights reserved.

Anticoagulants Also known as antithrombotic drugs Have no direct effect on a blood clot that is already formed Prevent intravascular thrombosis by decreasing blood coagulability Used prophylactically to prevent Clot formation (thrombus) An embolus (dislodged clot) Copyright © 2017, Elsevier Inc. All rights reserved.

Embolus Thromboembolic events Myocardial infarction (MI): embolus lodges in a coronary artery Stroke: embolus obstructs a brain vessel Pulmonary emboli: embolus in the pulmonary circulation Deep vein thrombosis (DVT): embolus goes to a vein in the leg Copyright © 2017, Elsevier Inc. All rights reserved.

Anticoagulants (Cont.)
Heparins Action: inhibit clotting factors IIa (thrombin) and Xa Unfractionated heparin: “heparin” Low-molecular-weight heparins (LMWHs) enoxaparin (Lovenox) dalteparin (Fragmin) Copyright © 2017, Elsevier Inc. All rights reserved.

Heparins (Cont.) Unfractionated heparin (heparin) Relatively large molecule that is derived from animal sources Frequent laboratory monitoring for bleeding times such as aPTT Heparin for catheter flush ( units/mL): no monitoring is needed Copyright © 2017, Elsevier Inc. All rights reserved.

Heparins (Cont.) LMWHs enoxaparin (Lovenox) and dalteparin (Fragmin) Synthetic smaller molecular structure More predictable anticoagulant response Frequent laboratory monitoring of bleeding times using tests such as aPTT not needed Copyright © 2017, Elsevier Inc. All rights reserved.

Warfarin (Coumadin) Inhibits vitamin K synthesis by bacteria in the gastrointestinal tract Inhibits production of vitamin K–dependent clotting factors II, VII, IX, and X, which are normally synthesized in the liver Final effect prevention of clot formation Copyright © 2017, Elsevier Inc. All rights reserved.

Direct thrombin inhibitors Action: inhibit thrombin (factor IIa) Human antithrombin III (Thrombate) lepirudin (Refludan) argatroban (Argatroban) bivalirudin (Angiomax) dabigatran (Pradaxa) Copyright © 2017, Elsevier Inc. All rights reserved.

Anticoagulants: Mechanism of Action
Vary, depending on drug Work on different points of the clotting cascade Prevent intravascular thrombosis by decreasing blood coagulability Do not lyse existing clots Copyright © 2017, Elsevier Inc. All rights reserved.

Anticoagulants: Indications
Used to prevent clot formation in certain settings in which clot formation is likely MI Unstable angina Atrial fibrillation Indwelling devices, such as mechanical heart valves Major orthopedic surgery Copyright © 2017, Elsevier Inc. All rights reserved.

Anticoagulants: Contraindications
Drug allergy Any acute bleeding process or high risk for such an occurrence Warfarin is strongly contraindicated in pregnancy. Other anticoagulants are rated in lower pregnancy categories (B or C). LMWHs are contraindicated in patients with an indwelling epidural catheter risk of epidural hematoma. Copyright © 2017, Elsevier Inc. All rights reserved.

Anticoagulants: Adverse Effects
Bleeding Risk increases with increased dosages May be localized or systemic May also cause: Heparin-induced thrombocytopenia Nausea, vomiting, abdominal cramps, thrombocytopenia, others Copyright © 2017, Elsevier Inc. All rights reserved.

Heparin-Induced Thrombocytopenia
Type I Gradual reduction in platelets Heparin therapy can generally be continued. Type II Acute fall in the number of platelets (more than 50% reduction from baseline) Discontinue heparin. Copyright © 2017, Elsevier Inc. All rights reserved.

Heparin-Induced Thrombocytopenia (Cont.)
Clinical manifestations Thrombosis that can be fatal. Treatment: thrombin inhibitors lepirudin and argatroban Use of warfarin: can cause skin necrosis and “purple toes” syndrome Copyright © 2017, Elsevier Inc. All rights reserved.

Treatment: Toxic Effects of Heparin
Symptoms: hematuria, melena (blood in the stool), petechiae, ecchymoses, and gum or mucous membrane bleeding Stop drug immediately. Intravenous (IV) protamine sulfate: 1 mg of protamine can reverse the effects of 100 units of heparin. Copyright © 2017, Elsevier Inc. All rights reserved.

Treatment: Toxic Effects of Warfarin
Discontinue the warfarin. May take 36 to 42 hours before the liver can resynthesize enough clotting factors to reverse the warfarin effects Vitamin K1 (phytonadione) can hasten the return to normal coagulation. High doses of vitamin K (10 mg) given IV will reverse the anticoagulation within 6 hours. Copyright © 2017, Elsevier Inc. All rights reserved.

Treatment: Toxic Effects of Warfarin (Cont.)
Caution: when vitamin K is given, warfarin resistance will occur for up to 7 days. Severe bleeding: transfusions of human plasma or clotting factor concentrates. Life-threatening bleeding from warfarin: Kcentra and Profiline IV vitamin K: risk of anaphylaxis. Risk is diminished by diluting it and giving it over 30 minutes. Copyright © 2017, Elsevier Inc. All rights reserved.

Drug Interactions: Anticoagulants
Enzyme inhibition of metabolism Displacement of the drug from inactive protein-binding sites Decrease in vitamin K absorption or synthesis by the bacterial flora of the large intestines Alteration in the platelet count or activity Copyright © 2017, Elsevier Inc. All rights reserved.

Heparin Natural anticoagulant obtained from the lungs or intestinal mucosa of pigs 10 to 40,000 units/mL DVT prophylaxis: 5000 units subcutaneously two or three times a day; does not need to be monitored when used for prophylaxis When heparin is used therapeutically (for treatment), continuous IV infusion. Measurement of aPTT (usually every 6 hours until therapeutic effects are seen) is necessary. Copyright © 2017, Elsevier Inc. All rights reserved.

Warfarin (Coumadin) Coumadin Most commonly prescribed oral anticoagulant Careful monitoring of the prothrombin time/international normalized ratio (PT/INR) A normal INR (without warfarin) is 1.0, but a therapeutic INR (with warfarin) ranges from 2 to 3.5, depending on the indication for use of the drug (e.g., atrial fibrillation, thromboprevention, prosthetic heart valve). Variations in certain genes, CYP2CP and VKORC1 Dietary considerations Copyright © 2017, Elsevier Inc. All rights reserved.

Audience Response System Question
A patient is receiving an IV infusion of heparin and was started on warfarin therapy the night before. Which statement is most correct? The patient is receiving a double dose of anticoagulants. The heparin therapy was ineffective, so the warfarin was started. The heparin provides anticoagulation until therapeutic levels of warfarin are reached. The heparin and warfarin work together synergistically to provide anticoagulation. Correct answer: C Rationale: Heparin has a faster onset and therefore is used to provide anticoagulation until therapeutic levels of warfarin are reached. Copyright © 2017, Elsevier Inc. All rights reserved. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Antiplatelet Drugs Prevent platelet adhesion aspirin cilostazol (Pletal) clopidogrel (Plavix) Prasugrel (Effient) Treprostinil (Remodulin) abciximab (ReoPro) eptifibatide (Integrilin) tirofiban (Aggrastat) anagrelide (Agrylin) dipyridamole (Persantine) Copyright © 2017, Elsevier Inc. All rights reserved.

Relationship between platelets and the clotting cascade
Copyright © 2017, Elsevier Inc. All rights reserved.

Antiplatelet Drugs: Indications and Adverse Effects
Antithrombotic effects Adverse effects Vary according to drug Copyright © 2017, Elsevier Inc. All rights reserved.

Thrombolytic Drugs Drugs that break down, or lyse, preformed clots Older drugs streptokinase and urokinase Current drugs alteplase (Activase, Cathflo Activase) reteplase (Retavase) tenecteplase (TNKase) Copyright © 2017, Elsevier Inc. All rights reserved.

Thrombolytic Drugs: Mechanism of Action
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 Copyright © 2017, Elsevier Inc. All rights reserved.

Thrombolytic Drugs: Indications
Acute MI Arterial thrombolysis DVT Occlusion of shunts or catheters Pulmonary embolus Acute ischemic stroke Copyright © 2017, Elsevier Inc. All rights reserved.

Thrombolytic Drugs: Adverse Effects
Bleeding Internal Intracranial Superficial Other effects Nausea, vomiting, hypotension, anaphylactoid reactions Cardiac dysrhythmias; can be dangerous Copyright © 2017, Elsevier Inc. All rights reserved.

A patient is receiving an IV 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? Monitor the site for further bleeding. Apply pressure to the site with a gauze pad. Slow the rate of infusion of the thrombolytic drug. Stop the infusion of the thrombolytic drug. Correct answer: B Rationale: The most common undesirable effect of thrombolytic therapy is internal, intracranial, and superficial bleeding. If invasive procedures must be performed or injections given, appropriate pressure should be applied to bleeding sites, and all areas of venous or arterial catheter insertion should be closely watched for bleeding. This type of superficial bleeding is to be expected and does not warrant cessation of the thrombolytic therapy. Copyright © 2017, Elsevier Inc. All rights reserved. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Antifibrinolytic Drugs
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 Copyright © 2017, Elsevier Inc. All rights reserved.

Antifibrinolytic Drugs (Cont.)
aminocaproic acid (Amicar) tranexamic acid (Cyklokapron) desmopressin Copyright © 2017, Elsevier Inc. All rights reserved.

Antifibrinolytic Drugs: Adverse Effects
Uncommon and mild Rare reports of thrombotic events Others include Dysrhythmia, orthostatic hypotension, bradycardia, headache, dizziness, fatigue, nausea, vomiting, abdominal cramps, diarrhea, others Copyright © 2017, Elsevier Inc. All rights reserved.

Nursing Implications Assess Patient history, medication history, allergies Contraindications Baseline vital signs, laboratory values Potential drug interactions History of abnormal bleeding conditions Copyright © 2017, Elsevier Inc. All rights reserved.

Heparin: Nursing Implications
IV doses are usually double checked with another nurse. Ensure that subcutaneous doses are given subcutaneously, not intramuscularly. Subcutaneous doses should be given in areas of deep subcutaneous fat and sites rotated. Copyright © 2017, Elsevier Inc. All rights reserved.

Heparin: Nursing Implications (Cont.)
Do not give subcutaneous doses within 2 inches of: The umbilicus, abdominal incisions, open wounds, scars, drainage tubes, or stomas Do not aspirate subcutaneous injections or massage the injection site. May cause hematoma formation Copyright © 2017, Elsevier Inc. All rights reserved.

Heparin: Nursing Implications (Cont.)
IV doses may be given by bolus or IV infusions. Anticoagulant effects are seen immediately. Laboratory values are done daily to monitor coagulation effects (aPTT). Protamine sulfate can be given as an antidote in case of excessive anticoagulation. Copyright © 2017, Elsevier Inc. All rights reserved.

LWMHs: Nursing Implications
Given subcutaneously in the abdomen Rotate injection sites. Protamine sulfate can be given as an antidote in case of excessive anticoagulation. Copyright © 2017, Elsevier Inc. All rights reserved.

Warfarin (Coumadin): 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 Copyright © 2017, Elsevier Inc. All rights reserved.

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? Pressure should be applied to the lump for 3 to 5 minutes. He will need to take two doses of warfarin tonight to prevent blood clotting. He needs to be examined for possible internal bleeding from the fall. As long as there is no bleeding, there is no concern. Correct answer: C Rationale: Careful examination will be needed to ensure that there is no hematoma or other internal bleeding as a result of the fall even if superficial bleeding is not noted. Copyright © 2017, Elsevier Inc. All rights reserved. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Warfarin (Coumadin): Nursing Implications
Many herbal products have potential interactions; increased bleeding may occur Capsicum pepper Garlic Ginger Ginkgo St. John’s wort Feverfew Copyright © 2017, Elsevier Inc. All rights reserved.

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. The concern with taking these two drugs together is increased risk of gastric ulcer. decreased action of the aspirin because of the interaction with the ginkgo. increased risk of bleeding because of the ginkgo. antagonism of the action of the aspirin because of the multivitamins. Correct answer: C Rationale: Ginkgo may cause some increased bleeding times, so taking aspirin with ginkgo may put the patient at a higher risk for bleeding episodes. Copyright © 2017, Elsevier Inc. All rights reserved. Elsevier items and derived items © 2009, 2005, 2001 by Saunders, an imprint of Elsevier Inc.

Anticoagulants: Patient Education
Education should include: Importance of regular laboratory testing Signs of abnormal bleeding Measures to prevent bruising, bleeding, and tissue injury Copyright © 2017, Elsevier Inc. All rights reserved.

Anticoagulants: Patient Education (Cont.)
Education should include: (Cont.) 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 Copyright © 2017, Elsevier Inc. All rights reserved.

Antiplatelet Drugs: Nursing Implications
Concerns and teaching tips same as for anticoagulants Drug–drug interactions Adverse reactions to report Monitoring for abnormal bleeding Copyright © 2017, Elsevier Inc. All rights reserved.

Thrombolytic Drugs: Nursing Implications
Follow strict manufacturer’s guidelines for preparation and administration. Monitor IV sites for bleeding, redness, and pain. Monitor for bleeding from gums, mucous membranes, nose, and injection sites. Observe for signs of internal bleeding (decreased blood pressure, restlessness, increased pulse). Copyright © 2017, Elsevier Inc. All rights reserved.

Case Study The nurse is caring for a patient receiving IV heparin therapy for treatment of a pulmonary embolus. The patient is being converted to warfarin (Coumadin) therapy. The following questions relate nursing considerations when caring for this patient. Copyright © 2017, Elsevier Inc. All rights reserved.

Case Study (Cont.) Nursing considerations for conversion of IV heparin to oral warfarin (Coumadin) therapy will include: immediate discontinuation of IV heparin and administration of oral warfarin (Coumadin) therapy only. overlapping therapy of IV heparin and warfarin are for at least 5 days. monitoring the INR and stopping the IV heparin when the INR is 1.0. Correct answer: B Rationale: When the oral anticoagulant warfarin is prescribed, therapy is often initiated while the patient is still receiving heparin. This overlapping is done purposefully to allow time for the blood levels of warfarin to rise so that when the heparin is eventually discontinued, therapeutic anticoagulation levels of warfarin will have been achieved. Recommendations for overlapping therapy of heparin and warfarin are for at least 5 days; the heparin is stopped after 5 days when the INR is above 2. Copyright © 2017, Elsevier Inc. All rights reserved.

Case Study (Cont.) 2. When converting from IV heparin to oral warfarin (Coumadin) therapy, the prescriber monitors which of the following to determine the next appropriate dose of warfarin? Platelet levels aPTT Red blood cell count PT/INR Correct answer: D Rationale: For conversion from heparin to an oral anticoagulant such as warfarin, the dose of the oral drug is the usual initial dosage amount, with the prescriber using the PT/INR levels to determine the next appropriate dosage of warfarin. When there is continuous therapeutic anticoagulation coverage and warfarin has reached therapeutic levels, the heparin or LMWH may be discontinued without tapering. Copyright © 2017, Elsevier Inc. All rights reserved.

Case Study (Cont.) 3. Which of the following should the nurse include when providing dietary teaching for the patient receiving warfarin (Coumadin) therapy? Avoid drinking large amounts of green tea. Cranberry juice will provide you with needed nutrients while taking Coumadin. You must never eat spinach. You can only eat lettuce once a month. Correct answer: A Rationale: For patients taking warfarin therapy, it is recommended to avoid eating or drinking large amounts of kale, spinach, Brussels sprouts, collard or mustard greens, lettuce, chard, and green tea. Beverages that may increase the effect of warfarin and to be avoided include cranberry juice and alcohol. Copyright © 2017, Elsevier Inc. All rights reserved.

Case Study (Cont.) 4. The patient accidentally takes too much of the prescribed warfarin (Coumadin) and is readmitted to the hospital with bleeding. The nurse anticipates administration of protamine sulfate. alteplase (Activase, Cathflo Activase). reteplase (Retavase). vitamin K. Correct answer: D Rationale: High doses of vitamin K (10 mg) given IV will reverse the anticoagulation of warfarin within 6 hours. Protamine sulfate is used to reverse heparin. Alteplase, and reteplase are thrombolytics. Copyright © 2017, Elsevier Inc. All rights reserved.

Coagulation Modifier Drugs

Similar presentations

Presentation on theme: "Coagulation Modifier Drugs"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Coagulation Modifier Drugs

Similar presentations

Presentation on theme: "Coagulation Modifier Drugs"— Presentation transcript:

Similar presentations

About project

Feedback