NUR 3420 Pharmacology PrepU Chapter 9

The provider orders heparin for a 35-year-old female client. The nurse administers the drug only after confirming that the client:

does not have peptic ulcer disease Explanation: Contraindications of heparin include GI ulcerations (e.g., peptic ulcer disease, ulcerative colitis), active bleeding, severe kidney or liver disease, severe hypertension, and recent surgery of the eye, spinal cord, or brain. The drug should be used cautiously in clients with non-severe hypertension.

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 Explanation: Heparin is frequently used to prevent postsurgical venous thromboembolism. Antiplatelet drugs do not have this indication, and vitamin K would increase the client's risks.

A nurse is preparing to discharge a female client newly prescribed warfarin (Coumadin). While assessing the client's knowledge of their drug, what would indicate that the client needs further instruction concerning her drug therapy?

"I take aspirin for my arthritis." Explanation: Increased bleeding can occur if a salicylate is taken in combination with warfarin. The nurse will instruct the client that she will have to stop taking aspirin. Walking, eating tomatoes, and drinking an occasional glass of wine should not interfere with the therapeutic effects of warfarin.

The nurse knows that teaching about warfarin (Coumadin) is successful if the client states:

"I will ask my health care provider about herbal supplements." Explanation: Many commonly used herbs and supplements have a profound effect on drugs used for anticoagulation. The other options indicate the client needs more teaching.

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." Explanation: 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.

The nurse is caring for a postoperative client receiving dalteparin prophylactically to prevent deep vein thrombosis. The nurse should perform which ongoing assessment(s) for safe administration of the drug? Select all that apply.

- Presence of dark tarry stools, or melena - Presence of pain, edema, redness in leg - Nasogastric drainage for presence of blood

An older client has been prescribed an anticoagulant. What statement made by the client assures the nurse that the discharge information was understood correctly? (Select all that apply.)

- "They may need to increase the dosage of this medication." - "It's really important that I have my blood tested on a regular basis." - "Starting or stopping any of my other medications could cause me to bleed."

The nurse is teaching a client and caregiver about the warfarin which has been prescribed to continue at home. The nurse determines the teaching session is successful when the client and caregiver correctly choose which instructions to follow? Select all that apply.

- Be consistent with your intake of foods containing vitamin K. - Do not change brands of warfarin without consulting the health care provider. - Take the drug at the same time every evening. - Do not take or stop taking other medications except on the advice of the health care provider.

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

2.4 Evaluation: When anticoagulant therapy is used, the INR is maintained between 2 and 3. The other values are not therapeutic.

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

A 38-year-old male with peptic ulcer disease Explanation: 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. Urticaria is a listed adverse effect of taking heparin and would therefore be expected. A patient who takes heparin would be advised to not drink heavily or smoke, but neither would have the safety risk posed by a patient with peptic ulcer. A patient with an accelerated heart rate and on heparin therapy would be at no special risk.

Bleeding resulting from the administration of heparin is treated with which substance?

Protamine Sulfate

The health care provider orders thrombolytic agents when treating a client diagnosed with acute myocardial infarction. When specifically considering this client, which drug should the nurse keep readily available when blood flow is reestablished?

Antidysrhythmics Explanation: When the thrombolytic agents are used in acute myocardial infarction, cardiac dysrhythmias may occur when blood flow is reestablished; antidysrhythmic drugs should be readily available.

A nurse is caring for a patient receiving the anticoagulant drug warfarin. What pre-administration assessments should the nurse perform before administering the drug to the patient?

Assess prothrombin time (PT) and INR. Evaluation: The nurse should assess the prothrombin time (PT) and INR before administering the anticoagulant drug warfarin to the patient. Observing for signs of thrombus formation, assessing for signs of bleeding, and monitoring for hypersensitivity reaction are the ongoing assessments performed in patients who are administered warfarin.

When a client is a receiving a continuous intravenous infusion of heparin 1,000 U/hr, what should the nurse do?

Avoid IM injections Explanation: The most commonly encountered adverse effect of the anticoagulants is bleeding, ranging from bleeding gums with tooth brushing to severe internal hemorrhage. Avoid all invasive procedures, including giving IM injections while the client is on heparin. It would not be necessary to assess for respiratory depression, measure hourly output, or monitor the BP hourly.

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 Explanation: Heparin, along with antithrombin, rapidly promotes the inactivation of factor X, which, in turn, prevents the conversion of prothrombin to thrombin. Heparin does not achieve its therapeutic effect through the excretion or inhibition of vitamin K or by inhibiting platelet aggregation.

A patient is prescribed warfarin to prevent the formation and extension of thrombus. The patient also takes a diuretic for the treatment of cardiac problems. What effect of interaction between the two drugs should the nurse monitor in the patient?

Decreased effectiveness of the anticoagulant Evaluation: The nurse should monitor for decreased effectiveness of warfarin as an effect of the interaction between the anticoagulant and the diuretic. The nurse need not monitor for the increased effectiveness of diuretics, the increased absorption of the anticoagulant, or the increased absorption of diuretics in the patient.

A client taking warfarin (Coumadin) tells the nurse she is having bleeding in the gums and teeth. When reviewing client history, the client states she has decided to try an herbal remedy. Which of the following is most likely the cause of increased bleeding?

Ginger Explanation: Warfarin should not be combined with any of the following substances, because they may have additive or synergistic activity and increase the risk for bleeding: celery, chamomile, clove, dong quai, feverfew, garlic, ginger, ginkgo biloba, ginseng, green tea, onion, passionflower, red clover, St. John's wort, and turmeric.

The client presents to the health care provider's office because the provider is unable to regulate the client's Coumadin dosage. During the interview, the nurse finds that the client began taking what substance, which might increase the effects of the warfarin?

Ginseng Explanation: Herbs commonly used that may increase the effects of warfarin include alfalfa, celery, clove, feverfew, garlic, ginger, ginkgo biloba, ginseng, and licorice.

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?

Heparin Explanation: 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). Vitamin K is used to treat the overdosage of warfarin. Alteplase and clopidogrel do not require antidotes.

A 75-year-old client presents to the health care provider's office with bleeding gums and multiple bruises. When the nurse reviews the client's drug history, the nurse finds that the client is prescribed aspirin 81 mg/d. What drug may cause increased bleeding when used in conjunction with the aspirin?

NSAIDs Evaluation: NSAIDs, which are commonly used by older adults, also have antiplatelet effects. Clients who take an NSAID daily may not need low-dose aspirin for antithrombotic effects.

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

Oral

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

PT and INR Explanation: 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 exhibits signs and symptoms of heparin overdose. The nurse would anticipate administering:

Protamine Sulfate Evaluation: Protamine sulfate is the antidote for heparin overdose. Vitamin K is the antidote for warfarin overdose. Urokinase is a thrombolytic. Drotrecogin alfa is a C-reactive protein that has anticoagulant effects.

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?

Presence of blood in urine or stools Evaluation: 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. Sleepiness, drowsiness, skin rash, and dizziness are not commonly identified adverse effects of the drug.

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?

Prevent extension of clots already present

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

Promotes the inactivation of clotting factors Explanation: Heparin blocks the formation of thrombin from prothrombin. Heparin does not bind to factors X and Xa. Heparin does not inactivate factor VIII.

A nurse is caring for a 64-year-old female client who is receiving IV heparin and reports bleeding from her gums. The nurse checks the client's laboratory test results and finds that she has a very high aPTT. The nurse anticipates that which drug may be ordered?

Protamine sulfate Evaluation: If a client who receives IV heparin is found to be highly anticoagulated, protamine sulfate may be prescribed. Protamine sulfate, which is a strong base, reacts with heparin, which is a strong acid, to form a stable salt, thereby neutralizing the anticoagulant effects of heparin. Protamine sulfate does not produce the same effects for coumadin, alteplase, or ticlopidine.

A nurse is caring for a client who is going home on warfarin (Coumadin). The nurse will schedule the client for what laboratory test to help evaluate therapeutic effects of the drug?

Prothrombin time (PT) and international normalized ratio (INR) Explanation: Evaluate for therapeutic effects of warfarin—prothrombin time (PT) 1.5 to 2.5 times the control value or ratio of PT to INR (international normalized ratio) of 2 to 3—to evaluate the effectiveness of the drug dose.

A client is to receive enoxaparin (Lovenox). The nurse would administer this drug by which route?

Subcutaneous injection Explanation: Enoxaparin (Lovenox) is administered via subcutaneous injection. Intramuscular (IM) administration is avoided because of the possibility of the development of local irritation, pain, or hematoma (a collection of blood in the tissue). Intravenous infusions are used with several anticoagulants such as heparin. Warfarin is given orally.

A client is being sent home with subcutaneous heparin after a total hip replacement. The nurse understands what symptom would indicate a serious drug reaction?

Tarry Stools Evaluation: Tarry stools would be an indication of gastrointestinal bleeds. The most common adverse effect of heparin is bleeding.

Warfarin typically takes 3 days to achieve its onset of action.

True Evaluation: Warfarin's onset of action is about 3 days; its effects last for 4 to 5 days.

Heparin is the anticoagulant of choice during lactation.

True Explanation: Although some adverse fetal affects have been reported with its use during pregnancy, heparin does not enter breast milk, and so it is the anticoagulant of choice if one is needed during lactation.

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 Explanation: Vitamin K is the antidote for warfarin.

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

aPPT Explanation: Before initiating therapy, it is important to review the client's aPTT, hematocrit, 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. The client's heart rate and pulse, electrolyte levels, and blood sugar levels would not be priority nursing assessments.

A 70-year-old resident of a long-term care facility has experienced increasing pain, swelling, and redness to her lower leg over the past 12 hours, prompting the care providers at the facility to have the woman brought to the local emergency department. Diagnostic testing has confirmed deep vein thrombosis (DVT) and an IV infusion of alteplase (Activase) has been initiated. Unlike anticoagulants, a thrombolytic such as alteplase can

break down existing clots Explanation: Unlike anticoagulants, thrombolytics are able to break down existing clots, not solely prevent the formation of new clots. Potentiation of vitamin K would exacerbate clotting and the pharmacodynamics of thrombolytics do not primarily affect platelet action.

The nurse is caring for a 76-year-old client who is receiving IV heparin 5000 units q4h. At the initiation of therapy, the client's control activated thromboplastin time (aPTT) was found to be 35 seconds. One hour prior to the next scheduled dose, aPTT is determined to be 92 seconds. Based on this result, the nurse will:

hold the dose and contact the provider. Explanation: During heparin therapy, aPTT values are typically maintained between 1.5 to 2.5 times the control value. Since an aPTT value of 92 seconds is greater than 2.5 times this client's control value, the anticoagulation effect is too great, and the health care provider should be notified.

A client is receiving warfarin. The nurse would expect to administer this drug by which route?

oral

The nurse explains to a client that angina can be caused by a thrombus forming in which anatomical location?

the heart Explanation: In coronary arteries, a thrombus may precipitate myocardial ischemia (angina or infarction). Assessment would focus on the coronary system, rather than any of the other presented options.

To monitor possible intermittent claudication, the nurse will assess for a thrombus lodging in what specific location?

the legs Evaluation: n peripheral arteries, a thrombus in peripheral circulation may cause intermittent claudication (pain in the legs with exercise) or acute occlusion. Assessment would focus on the legs, rather than any of the other presented options.