Chapter 26 Coagulation Modifier Drugs

Bleeding Internal Intracranial Superficial Other effects Nausea, vomiting, hypotension, anaphylactoid reactions Cardiac dysrhythmias; can be dangerous

Adverse effects thrombolytics

Capsicum pepper Garlic Ginger Ginkgo St. John's wort Feverfew -causes increased risk of bleeding

Warfarin and herbal reactions

Vitamin K

Warfarin antidote

-find out if right dose of heparin is being used

What is APTT used to measure?

B The aPTT value of 120 seconds is too prolonged. The heparin drip should be stopped per the provider order. The typical aPTT normal values for a patient on anticoagulant therapy are between 1.5 and 2.5 times the control value, with normal control values being between 25 and 35 seconds. The normal range for BUN is 7 to 20 mg/dL, and the normal platelet range is 150,000 to 400,000. Normal range for INR is 0.8 to 1.1. Note that heparin does not affect the INR or the BUN level.

A patient is receiving an intravenous heparin drip. Which laboratory value requires immediate action by the nurse? A. Platelet count of 150,000 mm3 B. Activated partial thromboplastin time (aPTT) of 120 seconds C. International normalized ratio (INR) of 1.0 D. Blood urea nitrogen (BUN) level of 12 mg/dL

B Warfarin works by decreasing the production of clotting factors. However, it takes 4 to 5 days for the body to use up present clotting factors and thus achieve a full therapeutic anticoagulant effect. Because of this, heparin is continued until this is achieved.

A patient is started on oral anticoagulant therapy while still receiving intravenous heparin. The patient is concerned about risk for bleeding. What is the nurse's best response? A. "Your concern is valid in that you are at an increased risk for bleeding, so I will call the doctor to discontinue the heparin." B. "It usually takes 4 to 5 days to achieve a full therapeutic effect for warfarin, so the heparin is continued to help prevent blood clots until the warfarin is working up to speed." C. "Because of your valve replacement, it is especially important for you to be fully anticoagulated, and the heparin and warfarin together are more effective than one alone." D. "Because you are now up and walking, you have a higher risk of blood clots and therefore need to be on both medications."

B Vitamin K is the antagonist for warfarin.

A patient who has been anticoagulated with warfarin (Coumadin) is admitted with gastrointestinal bleeding. The nurse will anticipate administering which substance? A. vitamin E B. vitamin K C. protamine sulfate D. calcium gluconate

B Patients taking an anticoagulant should not use medications that would further increase the risk of bleeding.

A patient who is taking an anticoagulant requests an aspirin for headache relief. What is the nurse's best action? A. Administer 650 mg of acetylsalicylic acid (ASA), and reassess pain in 30 minutes. B. Take advantage of a teachable moment to inform the patient of potential drug interactions with anticoagulants. C. Explain to the patient that ASA is contraindicated, and administer ibuprofen as ordered. D. Explain that the headache is an expected side effect and will subside shortly.

Bleeding Risk increases with increased dosages May be localized or systemic May also cause: Heparin-induced thrombocytopenia Nausea, vomiting, abdominal cramps, thrombocytopenia, others

Adverse effects anticoagulants

mechanism by which formed thrombi are lysed to prevent excessive clot formation and blood vessel blockage

Fibrinolysis

Inhibit the action or formation of clotting factors Prevent clot formation

Anticoagulant drugs

Inhibit the action or formation of clotting factors and prevent clots from forming

Anticoagulants

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.

Anticoagulants Contraindications

Uncommon and mild Rare reports of thrombotic events Others include Dysrhythmia, orthostatic hypotension, bradycardia, headache, dizziness, fatigue, nausea, vomiting, abdominal cramps, diarrhea, others

Antifibrinolytic Drug Adverse Effects

aminocaproic acid (Amicar) tranexamic acid (Cyklokapron) desmopressin

Antifibrinolytic Drug Examples

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

Promote blood coagulation

Antifibrinolytic/Hemostatic drugs

Promote blood coagulation

Antifibrinolytic/hemostatic drugs

Inhibit platelet aggregation Prevent platelet plugs

Antiplatelet drugs

Concerns and teaching tips same as for anticoagulants Drug-drug interactions Adverse reactions to report Monitoring for abnormal bleeding

Antiplatelet drugs Implications

Prevent platelet plugs from forming by inhibiting platelet aggregation

Antiplatelets

D Protamine sulfate binds with heparin in the bloodstream to inactivate it and thus reverse its effect.

Before emergency surgery, the nurse would anticipate administering which medication to a patient receiving heparin? A. vitamin K B. vitamin E C. phenytoin D. protamine sulfate

B Cilostazol is an antiplatelet drug, which works through inhibition of type 3 phosphodiesterase in the platelets and primarily lower-extremity blood vessels.

Cilostazol (Pletal) belongs to which drug class? A. Anticoagulant B. Antiplatelet C. Thrombolytic D. Antifibrinolytic

Thrombosis that can be fatal. Treatment: thrombin inhibitors lepirudin and argatroban Use of warfarin: can cause skin necrosis and "purple toes" syndrome

Clinical manifestations of Heparin Induced Thrombocytopenia

Inhibit vitamin K-dependent clotting factors II, VII, IX and X

Coumarins

Human antithrombin III (Thrombate) lepirudin (Refludan) argatroban (Argatroban) bivalirudin (Angiomax) dabigatran (Pradaxa)

Direct thrombin inhibitors

Inhibit thrombin (factor IIa)

Direct thrombin inhibitors

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

Drug Interactions Anticoagulants

thrombus that moves through blood vessels

Embolus

A Enoxaparin is a low-molecular-weight heparin.

Enoxaparin sodium (Lovenox) is an anticoagulant used to prevent and treat deep vein thrombosis and pulmonary embolism. This drug is in which drug group? A. Low-molecular-weight heparin B. Oral anticoagulant C. Glycoprotein IIb/IIIa inhibitor D. Thrombolytic drug

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.

Fibrinolytic System Process

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

Hemophilia

Alter platelet function without preventing the platelets from functioning

Hemorheologic drugs

General term for any process that stops bleeding

Hemostasis

Natural anticoagulant obtained from the lungs or intestinal mucosa of pigs 10 to 40,000 units/mL

Heparin

DVT prophylaxis: 5000 units subcutaneously two or three times a day; does not need to be monitored when used for prophylaxis

Heparin DVT Prophylaxis

IV doses may be given by bolus or IV infusions. Anticoagulant effects are seen immediately.

Heparin IV administration

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. 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

Heparin Nursing Implications

Protamine sulfate

Heparin antidote

Protamine sulfate can be given as an antidote in case of excessive anticoagulation.

Heparin antidote

Heparin for catheter flush (10-100 units/mL): no monitoring is needed

Heparin for catheter flush

Bind to antithrombin III, which turns off activated factor II, X, and IX

Heparin mechanism

Laboratory values are done daily to monitor coagulation effects (aPTT).

Heparin monitoring

Inhibit clotting factors IIa (thrombin) and Xa

Heparins

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

LMWH

Given subcutaneously in the abdomen Rotate injection sites. Protamine sulfate can be given as an antidote in case of excessive anticoagulation.

LMWH implications

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

Nursing Implications for these drugs

A, B, D Alteplase can cause bleeding as well as cardiac dysrhythmias. Vital sign changes can alert the nurse to these complications. Alteplase does not directly affect liver enzymes. Injections should not be administered intramuscularly because of the increased risk of bleeding.

Nursing care for a patient receiving alteplase (Activase) would include which action? (Select all that apply.) A. Record vital signs and report changes. B. Observe for signs and symptoms of bleeding. C. Monitor liver enzymes. D. Assess for cardiac dysrhythmias. E. Administer injections intramuscularly to prevent bleeding.

-find out if right dose of warfarin is being used -measures bleeding time -INR base line is 1.0

PT/INR test

-Importance of regular laboratory testing -Signs of abnormal bleeding -Measures to prevent bruising, bleeding, and tissue injury -use soft tooth brush when brushing teeth 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

Patient education

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

Patient monitoring on warfarin

Intravenous (IV) protamine sulfate: 1 mg of protamine can reverse the effects of 100 units of heparin.

Protamine sulfate ratio treatment

Action: inhibit factor fondaparinux (Arixtra) ivaroxaban (Xarelto) apixaban (Eliquis)

Selective factor Xa inhibitors

D The patient should reduce the risk of bleeding, such as using a soft toothbrush. The other choices are inaccurate.

The nurse evaluates and determines the patient has a good understanding of the discharge instructions regarding warfarin (Coumadin) when the patient responds with which statement? A. "I will double my dose if I forget to take it the day before." B. "I should keep taking ibuprofen for my arthritis." C. "I should decrease the dose if I start bruising easily." D. "I should use a soft toothbrush for dental hygiene."

B INR determination is a routine test to evaluate coagulation while patients are taking warfarin, not heparin. A therapeutic INR is 2 to 3.

The nurse interprets a patient's international normalized ratio (INR) value of 2.5. What is the meaning of this reported value? A. The patient is not receiving enough warfarin for a therapeutic effect. B. The patient's warfarin dose is therapeutic. C. The patient is not receiving enough subcutaneous heparin for a therapeutic effect. D. The patient is receiving a dangerously high amount of heparin.

D Storage recommendations for the drug include that it is to be stored in and dispensed from its original bottle. This is important because if not stored properly and with the desiccant-drying agent (which absorbs moisture) in the packaging cap, the substance in the drug is easily broken down and a loss of potency occurs. This would result in less therapeutic effectiveness. Additionally, the U.S. Food and Drug Administration (FDA) is alerting consumers that even though the label says to discard the drug after 30 days of opening the original container, recent data suggest that it can maintain its potency for up to 60 days if the cap is closed tightly after each use and the bottle is kept away from excessive moisture, heat, and/or cold. The FDA suggests that Pradaxa be kept in the original bottle or blister package and not stored or placed in any other type of container.

The nurse is caring for a patient who has recently been placed on dabigatran (Pradaxa). Which instruction will the nurse provide to the patient regarding storing the drug for home use? A. "Discard the drug 21 days of opening the original container." B. "Remove from original package and place in aluminum foil." C. "Refrigerate and keep away from direct sunlight." D. "Store the drug with the desiccant-drying agent in the packing cap."

B Heparin dosing is based on aPTT results. The PT is reflective of warfarin's anticoagulant effect.

The nurse would assess which laboratory value to determine the effectiveness of intravenous heparin? A. Complete blood count (CBC) B. Activated partial thromboplastin time (aPTT) C. Prothrombin time (PT) D. Blood urea nitrogen (BUN)

C If the patient develops a rash while taking one of the coagulation modifier drugs, the drug needs to be discontinued.

The nurse is caring for a patient who is being treated with one of the coagulation modifier drugs. The patient tells the nurse that he has developed a rash. What is the nurse's highest priority action? A. Notify the provider to obtain an order for a topical medication to apply to the rash. B. Monitor the area of the rash; this is an expected side effect of the medication. C. Notify the provider; the medication will need to be discontinued. D. Instruct the patient to wash the area with mild soap and water and leave open to the air.

D A platelet count of less than 100,000/mm3 indicates thrombocytopenia. This significantly increases the patient's risk of bleeding. Heparin should be withheld. In addition, thrombocytopenia at the onset of heparin therapy confounds the ability of the health care team to detect heparin-induced thrombocytopenia. The INR, aPTT, and potassium levels are all within normal limits.

The nurse is reviewing laboratory data before initiating a patient's heparin infusion. Which finding requires immediate action? A. Activated partial thromboplastin time (aPTT) of 37 seconds B. International normalized ratio (INR) of 1 C. Potassium 3.5 mEq/L D. Platelets 95,000/mm3

C Fondaparinux (Arixtra) is contraindicated with known allergy or in patients with a creatinine clearance less than 30 mL/min or a body weight of less than 50 kg.

The nurse is screening a patient for candidacy for treatment with fondaparinux (Arixtra). The nurse reviews the patient's laboratory test results and finds a creatinine clearance of 20 mL/min and a body weight of 48 kg. How will the nurse interpret these findings? A. The patient is a candidate for treatment with the medication based on a sufficient creatinine clearance and adequate body weight. B. The patient is not a candidate for treatment with the medication based only on an insufficient creatinine clearance. C. The patient is not a candidate for treatment with the medication based on both an insufficient creatinine clearance and an inadequate body weight. D. The patient is a candidate for treatment with the medication based on sufficient creatinine clearance and after body weight attains an adequate level.

A Aminocaproic acid (Amicar) is an antifibrinolytic medication that interacts with oral contraceptives and increases the risk of clot formation. Therefore, the nurse should instruct the patient not to take oral contraceptives during the therapy. Broccoli is rich in vitamin K. The consumption of broccoli does not reduce the effectiveness of the aminocaproic acid (Amicar). Following a low cholesterol diet reduces the risk of hypertension in the patient. Acetaminophen (Tylenol) does not interact with aminocaproic acid (Amicar), so the nurse will not instruct the patient to refrain from taking acetaminophen.

The nurse is teaching a patient who is receiving aminocaproic acid (Amicar) the measures to prevent adverse effects. Which statement made by the patient indicates the need for further teaching? A. "I should take oral contraceptives during the therapy." B. "I should refrain from eating broccoli during the therapy." C. "I should follow a low-cholesterol diet during the therapy." D. "I should not use any acetaminophen (Tylenol) during the therapy."

A, B, C, E Garlic, ginkgo, dong quai, and St. John's wort alter blood coagulation and may increase the risk of bleeding when given concurrently with oral anticoagulants. Glucosamine does not affect coagulation.

The nurse recognizes that patient teaching regarding warfarin (Coumadin) has been successful when the patient acknowledges an increased risk of bleeding with concurrent use of which herbal product? (Select all that apply.) A. Garlic B. Ginkgo C. Dong quai D. Glucosamine E. St. Johns wort

B A low-molecular-weight heparin is more predictable in its effect than regular heparin. Dalteparin is more expensive than heparin and is dosed based upon the patient's weight.

The patient asks what the difference is between dalteparin (Fragmin) and heparin. What is the nurse's best response? A. "There is really no difference, but dalteparin is preferred because it is less expensive." B. "Dalteparin is a low-molecular-weight heparin that has a more predictable anticoagulant effect." C. "I'm not really sure why some physicians choose dalteparin and some heparin, so you should ask your doctor." D. "The only difference is that heparin dosing is based on the patient's weight."

C Nausea accompanied by vomiting is an expected side effect of treatment with aspirin. Chest pain, edema, and itching are side effects that are more likely to be seen with use of clopidogrel.

The patient has been placed on aspirin as an antiplatelet drug. Which side effect is the patient most likely to experience? A. Chest pain B. Edema C. Nausea D. Itching

C Although it is important to monitor the patient's lab values, teach about limiting foods high in vitamin K, and administer a loading dose prior to beginning the maintenance IV dose, protamine sulfate must be kept readily available because it is the antidote for an overdose of heparin.

The patient is being treated with a continuous intravenous infusion of heparin. What is the nurse's highest priority? A. Ensure that the patient's laboratory values are monitored correctly. B. Ensure that the patient is taught dietary restrictions while on the medication. C. Ensure that protamine sulfate is readily available at all times. D. Ensure that a loading dose was initially administered when beginning treatment.

B The patient who is being treated with dabigatran (Pradaxa) should use all of the medication in the bottle within 60 days of opening the bottle.

The patient is being treated with dabigatran (Pradaxa) and opens a new bottle of the medication on July 1. The nurse will instruct the patient to discard any unused medication by which date? A. July 31 B. August 29 C. September 15 D. October 1

A A therapeutic INR is 2 to 3.5. The patient needs more warfarin to reach a therapeutic level.

The patient is receiving anticoagulant therapy. The international normalized ratio (INR) value for the patient today is 1.5. In response to this, the nurse could anticipate the health care provider placing which order? A. Administer an additional dose of warfarin (Coumadin). B. Hold the next dose of warfarin (Coumadin). C. Increase the heparin drip rate. D. Administer protamine sulfate.

Normal: 25-35 seconds -therapeutic effect: can be 1.5 to 2.5 times the baseline Warfarin prothrombin time normally 11-13 seconds baseline INR: 1.0 mechanical valves: 2.5 to 3.5 times prophylatic: 2.5 times

Therapeutic PTT

When heparin is used therapeutically (for treatment), continuous IV infusion. Measurement of aPTT (usually every 6 hours until therapeutic effects are seen) is necessary.

Therapeutic use of heparin

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

Thromboembolic Events

Older drugs streptokinase and urokinase Current drugs alteplase (Activase, Cathflo 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

-ase

Thrombolytic drug ending

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).

Thrombolytic drug implications

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

Thrombolytic drug indications

Lyse (break down) existing clots

Thrombolytic drugs

lyse/break down clots that have already formed

Thrombolytic drugs

blood clot

Thrombus

hematuria, melena (blood in the stool), petechiae, ecchymoses, and gum or mucous membrane bleeding

Toxicity of heparin signs and symptoms

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. 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.

Treatment of warfarin toxicity

Gradual reduction in platelets Heparin therapy can generally be continued.

Type I Heparin Induced Thrombocytopenia

Acute fall in the number of platelets (more than 50% reduction from baseline) Discontinue heparin.

Type II Heparin Induced Thrombocytopenia

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

Warfarin

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 Implications

A Clopidogrel (Plavix) is an antiplatelet drug indicated for thrombus prevention associated with strokes and myocardial infarction. Enoxaparin and heparin are anticoagulants. Alteplase is a thrombolytic drug.

Which medication has antiplatelet properties? A. clopidogrel B. enoxaparin C. heparin D. alteplase

C Dark green leafy vegetables are rich in vitamin K, which would antagonize the effects of warfarin. Therefore, it is important to maintain a consistent daily intake of vitamin K and avoid eating large amounts of these foods.

Which statement when made by the patient indicates deficient knowledge regarding warfarin? A. "I will avoid contact sports." B. "I will take my medication in the early evening each day." C. "I will increase the dark green leafy vegetables in my diet." D. "I will contact my physician if I develop excessive bruising."

B It is not recommended to massage the area of injection of anticoagulants due to the increased risk of hematoma formation.

While observing a patient self-administer enoxaparin (Lovenox), the nurse identifies the need for further teaching when the patient completes which action? A. Does not aspirate prior to injecting the medication B. Massages the site after administration of the medication C. Administers the medication greater than 2 inches away from the umbilicus D. Injects the medication and then waits 10 seconds before withdrawing the needle

A Tirofiban is a glycoprotein IIb/IIIa inhibitor that blocks the enzyme essential for platelet aggregation. This is given to prevent the formation of further clots and is faster acting than warfarin. Protamine sulfate is the antagonist for heparin, not an anticoagulant. Aminocaproic acid is an antifibrinolytic, the opposite of what is needed in this situation.

While preparing a patient with acute chest pain for an emergency angioplasty, the nurse would anticipate administering which medication to prevent platelet aggregation? A. tirofiban (Aggrastat) B. protamine sulfate C. warfarin (Coumadin) D. aminocaproic acid (Amicar)