Chapter 48: Drugs Affecting Blood Coagulation

A client with a history of trans-ischemic attacks (TIAs) was prescribed aspirin several weeks ago. Which assessment question should the nurse ask to monitor the client for the medication's adverse effects? (Select all that apply.)

"Have you experienced any dizziness?" "Have you been testing your stool for occult blood?" "Would you say your hearing has been affected?" "Are you experiencing any heartburn or indigestion?" Adverse aspirin effects include; hyperpnea, fever, coma, and CV collapse; nausea, dyspepsia, heartburn, epigastric discomfort, GI bleeding, occult blood loss, dizziness, tinnitus, difficulty hearing, anaphylactoid reaction, skin rash.

The nurse is preparing to administer protamine emergently to a client per instructions from the health care provider. The nurse concludes this is necessary due to an adverse reaction to which drug?

An overdosage of any anticoagulant may result in uncontrolled bleeding in the client. In most cases, discontinuation of the drug is usually sufficient to correct overdosage; however, if the bleeding is severe there are antidotes. Protamine is used to treat overdose of heparin and low-molecular-weight heparins (LMWHs).

After teaching a group of students about antiplatelet agents, the instructor determines that the teaching was successful when the students identify which drug as blocking the production of platelets in the bone marrow?

Anagrelide blocks the production of platelets in the bone marrow.

The health care provider discovers a clot in the client's left lower leg. Anticoagulant drugs are prescribed to prevent formation of new clots and to achieve which other effect?

Anticoagulant drugs are given to prevent formation of new clots and extension of clots already present.

Mr. Hon has been admitted to the hospital and placed on anticoagulant therapy. For what blood-related disorder is this therapy used?

Anticoagulants are used to treat hypercoagulation, or excessive coagulation. They prevent the blood from clotting unexpectedly and maintain the flow of blood.

A client with acute coronary syndrome is prescribed clopidogrel. Which additional medication will the nurse expect to be prescribed for this client?

Asprin. Clopidogrel is an adenosine diphosphate receptor antagonist used to prevent platelet aggregation. In acute coronary syndrome, clopidogrel is given with aspirin to prevent thrombus formation.

A 50-year-old client has undergone a bunionectomy and has been admitted to the postsurgical unit. What aspect of the client's medical history would contraindicate the use of heparin for deep vein thrombosis (DVT) prophylaxis?

GI ulcerations contraindicate the use of heparin since it is a frequent site of heparin-induced bleeding.

A female client is started on warfarin therapy. The client asks the nurse why she is no longer on heparin therapy. What differentiates heparin from warfarin?

Heparin is administered parenterally, while warfarin is administered orally. Heparin is administered parenterally, while warfarin is administered orally. Warfarin is administered after heparin therapy to complete treating a thrombus or embolism. Clients receiving heparin therapy will begin taking warfarin before they discontinue heparin. This overlap allows the warfarin to reach a therapeutic level before heparin is discontinued. However, both drugs are used to treat thrombosis and thromboembolic disorders and have equally serious adverse effects, such as bleeding. Anticoagulants, such as warfarin and heparin, prevent new clot formation or extension of an existing clot, while thrombolytics dissolve existing blood clots.

A nurse will use extreme caution when administering heparin to which patient?

Heparin should be administered with extreme caution to patients with peptic ulcer or liver disease or after surgery because those patients would have greater risk for hemorrhage or excessive blood loss.

The nurse is caring for a patient who is on thrombolytic therapy. The patient has a co-morbidity of renal insufficiency. What does the nurse know about the amount of heparin required to treat this patient?

If renal insufficiency exists, lower doses of heparin are required

A client is receiving low-molecular-weight heparin (LMWH) to prevent thromboembolic complications. The nursing student asks the instructor the reason why this treatment is given instead of heparin. What is the instructor's best explanation of the rationale for LMWH over heparin?

Low-molecular-weight heparins are associated with less thrombocytopenia than standard heparin.

The black box warning associated with warfarin concerns its risk of causing what condition?

The FDA has issued a black box warning for warfarin due to its risk of causing major or fatal bleeding.

There are two pathways that can be activated by the coagulation process. One pathway begins when factor XII is activated. The other pathway begins when there is trauma to a blood vessel. What are these pathways?

The coagulation process results from the activation of what has traditionally been designated the intrinsic or the extrinsic pathways. The intrinsic pathway, which is a relatively slow process, begins in the circulation with the activation of factor XII. The extrinsic pathway, which is a much faster process, begins with trauma to the blood vessel or surrounding tissues and the release of tissue factor, an adhesive lipoprotein released from the subendothelial cells. The terminal steps in both pathways are the same: the activation of factor X and the conversion of prothrombin to thrombin.

A 59-year-old client with vascular disorders is prescribed cilostazol. The nurse instructs the client that it is for the treatment of what condition?

This drug is intended for the treatment of intermittent claudication, which is an arterial disorder. *Pulmonary embolism, deep-vein thrombosis, and venous stasis are all venous disorders.

When administering tirofiban, the nurse would administer the drug intravenously over which time frame?

Tirofiban is administered intravenously over 30 minutes.

A client who has been treated with warfarin after cardiac surgery is found to have an INR of 9.0. Which medication will be administered to assist in the development of clotting factors?

Vitamin K is the antidote for warfarin overdosage. In this case, the client may be at the therapeutic level to control thrombus formation, but, due to the injury, it is important to control bleeding.

What values are used to monitor the effectiveness of warfarin therapy?

Warfarin dose is regulated according to the international normalized ratio (INR), which is based on prothrombin time (PT). PT and INR are assessed daily until a stable daily dose is reached. Thereafter, PT and INR are determined every few weeks for the duration of warfarin therapy.

A client is to receive abciximab. The nurse would expect to administer the drug by which route?

Abciximab is administered intravenously.

A direct thrombin inhibitor (DTI) has been added to a client's medication regimen to treat the onset of acute coronary syndrome. The nurse should anticipate administration by what route? Select all that apply.

IV, Oral. Both parenteral and oral DTIs are available.

The nurse instructs a client with a history of atrial fibrillation on warfarin. Which client statement indicates that teaching about the medication has been effective?

"I will avoid walking barefoot in the house and outdoors." Warfarin is an oral anticoagulant agent that is used to treat cardiovascular health problems. Because the medication thins the blood, the client should be instructed to avoid walking barefoot in the home and outdoors to reduce the risk for injury. The client should be instructed to use an electric razor when shaving to limit the risk for cuts.

A client recovering from joint replacement surgery is prescribed subcutaneous heparin injections. Which response will the nurse make when the client asks if the medication can be taken orally?

"The gastrointestinal tract does not absorb the drug, so it cannot be given by mouth."It is necessary to give heparin intravenously or through subcutaneous injection because the gastrointestinal tract does not absorb the drug. There is not an oral form of heparin.

Which client statement demonstrates an accurate understanding of the action of a prescribed anticoagulant?

"This medication will keep unnecessary clots from forming in my blood." An anticoagulant slows the body's normal blood-clotting processes to prevent harmful blood clots from forming. This type of drug is often called a "blood thinner"; however, it cannot dissolve any clots that have already formed and does not make your blood thin.

A 55-year-old client has been diagnosed with coronary artery disease and begun antiplatelet therapy. The client has asked the nurse why a "blood thinner like warfarin" hasn't been prescribed. What is the most likely rationale for the clinician's use of an antiplatelet agent rather than an anticoagulant?

Antiplatelet agents are more effective against arterial thrombosis; anticoagulants are more effective against venous thrombosis.Anticoagulants are more effective in preventing venous thrombosis than arterial thrombosis. Antiplatelet drugs are used to prevent arterial thrombosis

A nurse has an order to administer heparin. Before initiating this therapy, a priority nursing assessment will be the client's:

Before initiating therapy, it is important to review the client's aPTT, hematocrit, Hemaglobin, weight and platelet count. These tests provide baseline information on the client's blood clotting abilities and identify conditions that may cause heparin therapy to be contraindicated.

A 60-year-old client experienced a sudden onset of chest pain and shortness of breath and was subsequently diagnosed with a pulmonary embolism in the emergency department. The client has been started on an intravenous heparin infusion. How does this drug achieve therapeutic effect?

By inactivating clotting factors and thus stopping the coagulation cascade. Heparin, along with antithrombin, rapidly promotes the inactivation of factor X, which, in turn, prevents the conversion of prothrombin to thrombin.

A client with pneumonia develops deep vein thrombosis and is prescribed intravenous heparin. When reviewing the client's current medications, the nurse will alert the health care provider to what drug that could increase the effectiveness of the heparin?

Cephalosporin. Many medications interact with heparin, increasing or decreasing its effects. Drugs that increase the effects of heparin include cephalosporins. Digoxin, tetracycline, and antihistamines decrease the effectiveness of heparin.

A client is to receive clopidogrel. The nurse would expect to administer this agent by which route?

Clopidogrel is administered orally.

A nurse is preparing to administer an antiplatelet drug. Which medication would the nurse most likely administer?

Clopidogrel, it is an antiplatelet agent.

The nurse, providing postprocedural care for a client scheduled for a cardiac catheterization, will plan to implement which intervention to manage the risk for a common adverse effect of the procedure?

Direct pressure to arterial access site.Bleeding is the most common adverse effect, with most major bleeding occurring at the arterial access site for cardiac catheterization. If bleeding occurs and cannot be controlled with pressure, the drug infusion and heparin should be discontinued.

A client is to receive eptifibatide. The nurse would expect to administer this drug by which route

Eptifibatide is administered intravenously.

The pharmacology instructor is discussing heparin with the students. How would the instructor explain the action of heparin?

Heparin blocks the formation of thrombin from prothrombin. It promotes the inactivation of clotting factors

A nurse at a long-term care facility is conducting a medication reconciliation for a client who has just moved into the facility. The client is currently taking clopidogrel. The nurse is most justified suspecting that this client has a history of what condition?

Indications for use of clopidogrel include reduction of myocardial infarction, stroke, and vascular death in clients with atherosclerosis and in those after placement of coronary stents.

A client is being treated with heparin therapy for a pulmonary embolism. The nurse caring for this client knows that heparin:

It prevents the extension of the clot that has formed in lungs. Heparin interferes with the final steps of the clotting cascade. It is used to prevent the extension of a blood clot, particularly in patients with DVT or PE.

A client is receiving heparin. Which would the nurse use to monitor the effects of the drug?

Partial thromboplastin time. Heparin's effectiveness is monitored by the results of the partial thromboplastin time. The INR and PT are used to monitor warfarin.

A client with a history of clot formation is scheduled for bowel resection due to colorectal cancer. What anticoagulant agent will be administered prophylactically?

Prophylactically, low doses of heparin are given to prevent thrombus formation in clients having major abdominal surgery

Anticoagulant drugs are given to prevent formation of new clots and extension of clots already present.

Protamine sulfate is the antidote for heparin overdose. Vitamin K is the antidote for warfarin overdose. Urokinase is a thrombolytic.

A client accidentally ingested extra doses of warfarin at home and now presents with an elevated INR and bleeding. Which medication will the nurse prepare as prescribed to administer along with vitamin K?

Prothrombin complex concentrate. Urgent reversal of warfarin overdosage in adults with acute major bleeding can be accomplished with prothrombin complex concentrate (PCC). The drug should be administered as prescribed and concurrently with vitamin K to maintain factor levels once the effects of PCC have diminished.

A nurse is caring for a client receiving warfarin drug therapy. The client informs the nurse that he is also taking chamomile, which is an herbal remedy. The nurse would alert the client to which adverse effects?

The nurse should inform the client about the increased risk for bleeding, which is an effect of the interaction between warfarin and the herb

A client is receiving anticoagulant therapy and has an INR done. Which result would the nurse interpret as being therapeutic?

When anticoagulant therapy is used, the INR is maintained between 2 and 3.5

A stable daily dose of warfarin is reached when which parameter is achieved?

When warfarin is started, PT and INR should be assessed daily until a stable daily dose is reached (the dose that maintains PT and INR within therapeutic ranges and does not cause bleeding).

A 67-year-old man enters the emergency department reporting severe chest pain that is radiating down the left arm. He is diagnosed with a myocardial infarction. What drug does the nurse anticipate the health care provider ordering for this client?

Alteplase is a thrombolytic, and its action is to lyse a clot. It is indicated for use during an acute myocardial infarction. It is also used for pulmonary embolism

To compensate for clopidogrel's slow onset of action, the nurse should anticipate implementing which intervention?

Administering a one-time loading dose that is higher than the maintenance dose. Effective dose-dependent prevention of platelet aggregation can be seen within 2 hours of a single oral dose of clopidogrel, but the onset of action is slow, so a loading dose of 300 to 600 mg is usually administered.

A postsurgical client possesses numerous risk factors for venous thromboembolism, including a previous deep vein thrombosis. What drug would the nurse anticipate administering while this client recovers in the hospital?

Heparin is frequently used to prevent postsurgical venous thromboembolism.

The nurse educates a client diagnosed with atrial fibrillation about the prescribed warfarin. Which client statements establish the need for further clarification? "I will stop eating green leafy vegetables, broccoli, yogurt, or cheese."

The nurse needs to clarify teaching regarding the intake of foods rich in Vitamin K. The client should not avoid eating foods with Vitamin K, but eat consistent amounts every day so therapeutic levels for the warfarin may be maintained. The client has an adequate understanding of the importance of keeping lab appointments for PT and INR levels used to monitor and regulate the warfarin dosage. The client should take the warfarin the same tie each day to maintain consistent blood levels of the drug. The client should not drink alcohol unless the primary care provider approves it, and instructs the client as to how much and how often. Alcohol will increase the risk for bleeding.

A male client is receiving heparin by continuous intravenous infusion. The nurse will instruct the client and family members to report what should it occur?

The nurse should instruct the client and family members to report the presence of blood in urine or stools and any bleeding from the gums, nose, vagina, or wounds. The anticoagulation properties of heparin can sometimes result in abnormal bleeding.

Which would the nurse identify as the end of the intrinsic pathway?

Thrombin formation. Thrombin formation occurs at the end of the intrinsic pathway. The first reaction to a blood vessel injury is local vasoconstriction. In addition, injury then exposes blood to the collagen and other substances under the endothelial lining of the vessel causing platelet aggregation

A 73-year-old client receiving warfarin (Coumadin) has blood in the urinary drainage bag this morning. After reporting these observations to the health care provider, the nurse will expect to administer what substance?

Vitamin K. It is the antidote for warfarin.