Chapter 26: Coagulation Modifier Drugs

The nurse notes a patient's international normalized ratio (INR) value of 2.5. What is the meaning of this reported value? A. The patient's warfarin dose is within the therapeutic range. B. The patient needs the subcutaneous heparin dose increased. C. The patient is not receiving enough warfarin for a therapeutic effect. D. The patient is receiving too much heparin and is at risk for bleeding.

A. The patient's warfarin dose is within the therapeutic range. INR determination is a routine test to evaluate coagulation while patients are taking warfarin, not heparin. A therapeutic INR is 2 to 3.

A patient has had recent mechanical heart valve surgery and is receiving anticoagulant therapy. While monitoring the patient's laboratory work, the nurse interprets that the patient's international normalized ratio (INR) level of 3 indicates that a. the patient is not receiving enough warfarin to have a therapeutic effect. b. the patient's warfarin dose is at therapeutic levels. c. the patient's intravenous heparin dose is dangerously high. d. the patient's intravenous heparin dose is at therapeutic levels

ANS: B A normal INR (without warfarin) is 1.0, whereas 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).

A patient is being discharged on anticoagulant therapy. The nurse will include in the patient-education conversation that it is important to avoid herbal products that contain which substance? a. Valerian b. Ginkgo c. Soy d. Saw palmetto

ANS: B Capsicum pepper, feverfew, garlic, ginger, ginkgo, St. John's wort, and ginseng are some herbals that have potential interactions with anticoagulants, especially with warfarin.

A patient is receiving heparin therapy as part of the treatment for a pulmonary embolism. The nurse monitors the results of which laboratory test to check the drug's effectiveness? a. Bleeding times b. Activated partial thromboplastin time (aPTT) c. Prothrombin time/international normalized ratio (PT/INR) d. Vitamin K levels

ANS: B Ongoing aPTT values are used to monitor heparin therapy. PT/INR is used to monitor warfarin therapy. The other two options are not used to monitor anticoagulant therapy.

A patient who has been anticoagulated with warfarin (Coumadin) has been admitted for gastrointestinal bleeding. The history and physical examination indicates that the patient may have taken too much warfarin. The nurse anticipates that the patient will receive which antidote? a. vitamin E b. vitamin K c. protamine sulfate d. potassium chloride

ANS: B Vitamin K is given to reverse the anticoagulation effects of warfarin toxicity. Protamine sulfate is the antidote for heparin overdose. The other options are incorrect.

A patient who is taking warfarin (Coumadin) therapy has a headache and calls the prescriber's office to ask about taking a pain reliever. The nurse expects to receive instructions for which type of medication? a. aspirin tablets b. ibuprofen (Advil) c. acetaminophen (Tylenol) d. An opioid

ANS: C Acetaminophen should be safe in regular doses; high doses, however, as well as other nonsteroidal antiinflammatory drugs and aspirin, may cause an increased anticoagulant effect. Taking an opioid for a headache may not be appropriate.

The nurse notes in the patient's medication orders that the patient will be starting anticoagulant therapy. What is the primary goal of anticoagulant therapy? a. Stabilizing an existing thrombus b. Dissolving an existing thrombus c. Preventing thrombus formation d. Dilating the vessel around a clot

ANS: C Anticoagulants prevent thrombus formation but do not dissolve or stabilize an existing thrombus, nor do they dilate vessels around a clot.

A patient has been instructed to take one enteric-coated low-dose aspirin a day as part of therapy to prevent strokes. The nurse will provide which instruction when providing patient teaching about this medication? a. Aspirin needs to be taken on an empty stomach to ensure maximal absorption. b. Low-dose aspirin therapy rarely causes problems with bleeding. c. Take the medication with 6 to 8 ounces of water and food. d. Coated tablets may be crushed if necessary for easier swallowing.

ANS: C Enteric-coated aspirin is best taken with 6 to 8 ounces of water and with food to help decrease gastrointestinal upset. Enteric-coated tablets should not be crushed. Risk for bleeding increases with aspirin therapy, even at low doses.

A patient has received an overdose of intravenous heparin, and is showing signs of excessive bleeding. Which substance is the antidote for heparin overdose? a. vitamin E b. vitamin K c. protamine sulfate d. potassium chloride

ANS: C Protamine sulfate is a specific heparin antidote and forms a complex with heparin, completely reversing its anticoagulant properties. Vitamin K is the antidote for warfarin (Coumadin) overdose. The other options are incorrect.

A patient will be receiving a thrombolytic drug as part of the treatment for acute myocardial infarction. The nurse explains to the patient that this drug is used for which purpose? a. To relieve chest pain b. To prevent further clot formation c. To dissolve the clot in the coronary artery d. To control bleeding in the coronary vessels

ANS: C Thrombolytic drugs lyse, or dissolve, thrombi. They are not used to prevent further clot formation or to control bleeding. As a result of dissolving of the thrombi, chest pain may be relieved, but that is not the primary purpose of thrombolytic therapy.

When administering heparin subcutaneously, the nurse will follow which procedure? a. Aspirating the syringe before injecting the medication b. Massaging the site after injection c. Applying heat to the injection site d. Using a - to -inch 25- to 28-gauge needle

ANS: D A - to -inch 25- to 28-gauge needle is the correct needle to use for a subcutaneous heparin injection. The other options would encourage hematoma formation at the injection site.

A patient is receiving thrombolytic therapy, and the nurse monitors the patient for adverse effects. What is the most common undesirable effect of thrombolytic therapy? a. Dysrhythmias b. Nausea and vomiting c. Anaphylactic reactions d. Internal and superficial bleeding

ANS: D Bleeding, both internal and superficial, as well as intracranial, is the most common undesirable effect of thrombolytic therapy. The other options list possible adverse effects of thrombolytic drugs, but they are not the most common effects.

A patient has been prescribed warfarin (Coumadin) in addition to a heparin infusion. The patient asks the nurse why he has to be on two medications. The nurse's response is based on which rationale? a. The oral and injection forms work synergistically. b. The combination of heparin and an oral anticoagulant results in fewer adverse effects than heparin used alone. c. Oral anticoagulants are used to reach an adequate level of anticoagulation when heparin alone is unable to do so. d. Heparin is used to start anticoagulation so as to allow time for the blood levels of warfarin to reach adequate levels.

ANS: D 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. The full therapeutic effect of warfarin does not occur until 4 to 5 days after the first dose. This overlap of activity is required in patients who have been receiving heparin for anticoagulation and are to be switched to warfarin so that prevention of clotting is continuous.

The nurse is giving discharge instructions to a patient prescribed warfarin (Coumadin) for atrial fibrillation. Which statement by the patient indicates a need for further instruction from the nurse? A. "I will take my medication in the early evening each day." B. "I will contact my health care provider if I develop excessive bruising." C. "I will increase the dark green leafy vegetables in my diet." D. "I will avoid activities that have a risk for injury such as contact sports."

C. "I will increase the dark green leafy vegetables in my diet." 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.

A patient is prescribed oral anticoagulant therapy while still receiving IV heparin infusion. The patient is concerned about risk for bleeding. What is the nurse's best response? A. "Bleeding is a common adverse effect of taking warfarin. If bleeding occurs, your health care provider will prescribe an injection of medication to stop the bleeding." B. "Because of your mechanical valve replacement, it is especially important for you to be fully anticoagulated, and the heparin and warfarin together are more effective than one alone." C. "Because you are now getting out of bed and walking around, you have a higher risk of blood clot formation and therefore need to be on both medications." D. "It usually takes 4 to 5 days to achieve a full therapeutic effect for warfarin, so the heparin infusion is continued to help prevent blood clots until the warfarin reaches its therapeutic effect."

D. "It usually takes 4 to 5 days to achieve a full therapeutic effect for warfarin, so the heparin infusion is continued to help prevent blood clots until the warfarin reaches its therapeutic effect." 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.

Which medication is an antiplatelet drug? A. Clopidogrel (Plavix) B. Alteplase (Activase) C. Enoxaparin (Lovenox) D. Heparin (Hemochron)

A. Clopidogrel (Plavix) Clopidogrel (Plavix) is an antiplatelet drug. Enoxaparin and heparin are anticoagulants. Alteplase is a thrombolytic drug.

The nurse recognizes that the patient understands the teaching about warfarin (Coumadin) when the patient verbalizes an increased risk of bleeding with concurrent use of which herbal product? (Select all that apply.) Select all that apply. A. Garlic B. St. John's wort C. Glucosamine D. Dong quai E. Ginkgo

A. Garlic B. St. John's wort D. Dong quai E. Ginkgo 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 would assess which laboratory value to determine the effectiveness of intravenous heparin (Hemochron)? A. Complete blood count B. Activated partial thromboplastin time (aPTT) C. Blood urea nitrogen D. Prothrombin time (PT)

B. Activated partial thromboplastin time (aPTT) Heparin dosing is based on aPTT results. The PT is reflective of warfarin's anticoagulant effect.

A patient who is prescribed an anticoagulant requests an aspirin (acetylsalicylic acid) for headache relief. What is the nurse's best action? A. Administer 650 mg of acetylsalicylic acid and reassess pain in 30 minutes. B. Inform the patient of potential drug interactions with anticoagulants. C. Explain that a common initial adverse effect is a headache for this drug. D. Explain that acetylsalicylic acid is contraindicated and administer ibuprofen.

B. Inform the patient of potential drug interactions with anticoagulants. Patients taking an anticoagulant should not use medications that would further increase the risk of bleeding.

Before emergency surgery, the nurse would anticipate administering which medication to a patient receiving heparin? A. Vitamin K (Phytonadione) B. Protamine (Protamine sulfate) C. Phenytoin (Dilantin) D. Vitamin E

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

The nurse is caring for a patient admitted with gastrointestinal bleeding who is anticoagulated with warfarin (Coumadin). Which medication should the nurse anticipate administering? A. Vitamin E B. Vitamin K (Phytonadione) C. Protamine (Protamine sulfate) D. Calcium gluconate

B. Vitamin K (Phytonadione) Vitamin K is the antagonist for warfarin.

The nurse determines the patient has a good understanding of the discharge instructions regarding warfarin (Coumadin) with which patient 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 use a soft toothbrush for dental hygiene." D. "I should decrease the dose if I start bruising easily."

C. "I should use a soft toothbrush for dental hygiene." The patient should reduce the risk of bleeding, such as using a soft toothbrush. The other choices are inaccurate.

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

C. Low-molecular-weight heparin Enoxaparin is a low-molecular-weight heparin.

While observing a patient self-administer enoxaparin (Lovenox), the nurse identifies the need for further teaching when the patient performs which self-injection action? A. Massages the site after administration of the medication B. Does not aspirate before injecting the medication C. Administers the medication into subcutaneous (fatty) tissue D. Injects the medication greater than 2 inches away from the umbilicus

A. Massages the site after administration of the medication It is not recommended to massage the area of injection of anticoagulants because of the increased risk of hematoma formation.

For a patient receiving an IV infusion of alteplase (Activase), which nursing actions should be taken? (Select all that apply.) Select all that apply. A. Record vital signs and report changes. B. Assess for cardiac dysrhythmias. C. Observe for signs and symptoms of bleeding. D. Administer injections intramuscularly. E. Monitor for an increase in liver enzymes.

A. Record vital signs and report changes. B. Assess for cardiac dysrhythmias. C. Observe for signs and symptoms of bleeding. 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.

The nurse is reviewing new medication orders for a patient who has an epidural catheter for pain relief. One of the orders is for enoxaparin (Lovenox), a low-molecular-weight heparin (LMWH). What is the nurse's priority action? a. Give the LMWH as ordered. b. Double-check the LMWH order with another nurse, and then administer as ordered. c. Stop the epidural pain medication, and then administer the LMWH. d. Contact the prescriber because the LMWH cannot be given if the patient has an epidural catheter.

ANS: D LMWHs are contraindicated in patients with an indwelling epidural catheter; they can be given 2 hours after the epidural is removed. This is very important to remember, because giving an LMWH with an epidural has been associated with epidural hematoma.