Ch 26 - Coagulation Modifier Drugs
A patient has received an overdose of enoxaparin (Lovenox). The order was for 30 mg, but the patient received 90 mg. The nurse notes that the patient is showing signs of bleeding (oozing blood from the intravenous sites, increased bruising) and notifies the physician, who prescribes protamine sulfate to cover the excess amount of enoxaparin that the patient received. Calculate how much protamine sulfate the patient will receive.
60 mg Protamine sulfate is used to reverse the effects of low-molecular-weight heparins (LMWHs). A 1-mg dose of protamine is administered for each milligram of the LMWH. This patient received 60 mg of enoxaparin more than the ordered dose of 30 mg; therefore, 60 mg of protamine sulfate will be used as an antidote.
An elderly patient has had hip surgery and will be receiving heparin, 4000 units subcutaneously every 12 hours. The heparin is available in vials of 5000 units/mL. Calculate how much heparin the nurse will administer for this dose.
0.8 mL 5000 units : 1 mL :: 4000 units : x mL
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
Activated partial thromboplastin time (aPTT) 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.
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.
Contact the prescriber because the LMWH cannot be given if the patient has an epidural catheter. 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.
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
Ginkgo 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 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.
Heparin is used to start anticoagulation so as to allow time for the blood levels of warfarin to reach adequate levels. 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.
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
Internal and superficial bleeding 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.
The nurse is preparing to administer dipyridamole (Persantine). Which statement about this drug is true? a. It has antiinflammatory and antipyretic properties. b. It has analgesic properties as well as antithrombotic effects. c. It is useful in reducing the risk for fatal and nonfatal thrombotic stroke. d. It is used with warfarin to prevent postoperative thromboembolic complications.
It is used with warfarin to prevent postoperative thromboembolic complications. Dipyridamole (Persantine) is used as an adjunct to warfarin in the prevention of postoperative thromboembolic complications. The other options are incorrect.
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
Preventing thrombus formation Anticoagulants prevent thrombus formation but do not dissolve or stabilize an existing thrombus, nor do they dilate vessels around a clot.
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
Protamine sulfate 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 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.
Take the medication with 6 to 8 ounces of water and food. 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 will be taking dabigatran (Pradaxa) as part of treatment for chronic atrial fibrillation. Which statements about dabigatran are true? (Select all that apply.) a. The dose of dabigatran is reduced in patients with decreased renal function. b. Bleeding is the most common adverse effect. c. Potassium chloride is given as an antidote in cases of overdose. d. Dabigatran levels are monitored by measuring prothrombin time/international normalized ratio (PT/INR) results. e. This drug is a prodrug and becomes activated in the liver.
The dose of dabigatran is reduced in patients with decreased renal function. Bleeding is the most common adverse effect. This drug is a prodrug and becomes activated in the liver. Dabigatran is excreted extensively in the kidneys, and the dose is dependent upon renal function. The normal dose is 150 mg twice daily, but it must be reduced to 75 mg twice daily if creatinine clearance is less than 30 mL/min. The most common and serious side effect is bleeding. Dabigatran is a prodrug that becomes activated in the liver. There is no antidote to dabigatran. 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
To dissolve the clot in the coronary artery 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 1/2- to 5/8-inch 25- to 28-gauge needle
Using a 1/2- to 5/8-inch 25- to 28-gauge needle A 1/2 to 5/8-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 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
Vitamin K 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
acetaminophen (Tylenol) 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.
A patient has had recent prosthetic 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 2.5 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.
the patient's warfarin dose is at therapeutic levels. 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).
