Ch 52 Anticoagulant, Antiplatelet, and Thrombolytic Drugs

Which adverse effect of heparin may be seen during pregnancy? A. Osteoporosis B. Severe bleeding C. Abnormal uterine contractions D. Suppression of uterine contractions

A. Heparin is safe to a fetus but may cause osteoporosis in a pregnant woman. Severe bleeding and abnormal or suppressed uterine contractions are not associated with heparin.

The nurse is reviewing a client's current medication therapy and suspects hematuria. Which medication is responsible for the client's condition? A. Warfarin B. Cimetidine C. Phenazopyridine D. Nitrofurantoin

A. Warfarin is an anticoagulant. Anticoagulants may cause hematuria, which is the presence of blood in the urine. Cimetidine is an antihistamine. Antihistamines affect the normal contraction and relaxation of the urinary bladder. Phenazopyridine and nitrofurantoin cause urine discoloration.

A client is receiving warfarin. The nurse explains the need for careful regulation of dietary intake of vitamin K. What is the rationale of the nurse's teaching? A. Vitamin K promotes platelet aggregation B. Vitamin K promotes ionization of blood calcium C. Vitamin K promotes fibrinogen formation by the liver D. Vitamin K promotes prothrombin formation by the liver

D. Vitamin K promotes the liver's synthesis of prothrombin, an important blood clotting factor, and will reverse the effects of warfarin. Platelet aggregation and fibrinogen formation by the liver are not promoted by vitamin K. Vitamin K does not affect calcium ionization.

low-molecular-weight heparin

enoxaparin

heparin unfractionated

heparin

A client begins therapy with a new medication. One month later the client notices blood in the urine. Which drug does the nurse anticipate as the cause? A. Warfarin B. Nifedipine C. Nitrofurantoin D. Phenazopyridine

A. Warfarin is an anticoagulant medication and could result in blood in urine, a condition known as hematuria. Nifedipine is a calcium channel blocker that could affect the ability of the urinary bladder or sphincter to contract and relax normally. Nitrofurantoin is used to treat UTIs but can cause alteration in urine color to a dark yellowish-brown. Phenazopyridine, a bladder analgesic used to treat pain associated with UTIs, changes the color of urine to orange or red.

A client is admitted to the ED with crushing chest pain. A diagnosis of acute coronary syndrome is suspected. The nurse expects that the client's initial treatment will include which medication? A. Aspirin B. Midazolam C. Gabapentin D. Alprazolam

A. Early administration of aspirin in the setting of acute MI has been demonstrated to significantly reduce mortality. Aspirin inhibits the action of platelets, preventing their ability to clump together and form clots. The mechanism of acute coronary syndrome usually is ruptured plaque in one of the coronary arteries with clot formation obstructing blood flow. Prompt administration of an antiplatelet agent, such as aspirin, significantly reduces damage and can be lifesaving, the earlier the better; hence the reason why it is part of emergency management treatment. Gabapentin is an anticonvulsant and is not the drug of choice to relieve the pain associated with an MI. Midazolam HCl is a sedative-hypnotic that is used for its calming effect, but it will not relieve the pain of an MI. Alprazolam is an anxiolytic that is used for its calming effect, but it will not relieve the pain of an MI.

A client who had a femoropopliteal bypass graft is receiving clopidogrel postoperatively. What should the nurse teach the client related to the medication? A. Eliminate starches and red meats from the diet B. Eat more roughage if constipation occurs C. Report any occurrence of multiple bruises D. Take the medication on an empty stomach

C. Clopidogrel is a platelet aggregation inhibitor that decreases the probability of clots forming where the graft was placed, but it also increases bleeding tendencies when the dosage is excessive. Clopidogrel does not interact with starches or red meats, which are permitted in the diet. Diarrhea, not constipation, is more likely to occur with clopidogrel. Clopidogrel should be taken with food to decrease the side effects of gastric discomfort, diarrhea, and GI bleeding.

Three weeks after a client gives birth, a DVT develops in her left leg, and she is admitted to the hospital for bed rest and anticoagulant therapy. Which anticoagulant does the nurse expect to administer? A. Clopidogrel B. Warfarin C. Heparin D. Enoxaparin

C. Heparin is the medication of choice during the acute phase of a DVT; it prevents conversion of fibrinogen to fibrin and of prothrombin to thrombin. Clopidogrel is a platelet aggregate inhibitor and is used to reduce the risk of a brain attack. Warfarin, a long-acting oral anticoagulant, is started after the acute stage has subsided; it is continued for 2-3 months. A low-molecular-weight heparin (e.g., enoxaparin) is not administered during the acute stage; it may be administered later to prevent future DVTs.

A client is receiving warfarin for a pulmonary embolism. Which drug is often contraindicated when taking warfarin? A. Atenolol B. Ferrous sulfate C. Chlorpromazine D. Acetylsalicylic acid

D. Acetylsalicylic acid can cause decreased platelet aggregation, increasing the risk for undesired bleeding that may occur with administration of anticoagulants. It should not be administered unless specifically prescribed, usually by a cardiologist or other specialist, to manage serious risks of thrombosis. Ferrous sulfate does not affect warfarin; it is used for RBC synthesis. Atenolol is a beta-blocker that reduces BP; it does not affect bleeding. Chlorpromazine is a neuroleptic; it does not affect bleeding.

A client with a history of pulmonary emboli is taking warfarin daily. The nurse teaches the client about foods that are appropriate to consume when taking this medication. The nurse evaluates that the client needs further teaching when the client makes which statement? A. "Eggs provide a good source of iron, which is needed to prevent anemia" B. "Yellow vegetables are high in vitamin A and should be included in the diet" C. "Fish and shrimp are iodine-rich food sources that can prevent hypothyroidism" D. "Dark green leafy vegetables are high in vitamin K so I should eat them more often"

D. Foods high in vitamin K should be limited to the usual amounts eaten by the client when establishing the prothrombin time/international normalized ratio (PT/INR) because vitamin K is part of the body's blood-clotting mechanism and will counter the effects of warfarin if eaten in excess. Foods containing protein, iron, vitamin A, and iodine are permitted because they are unrelated to blood clotting.

A nurse is caring for a pregnant client with thrombophlebitis. Which anticoagulant medication may be prescribed? Select all that apply. A. Heparin B. Clopidogrel C. Warfarin D. Enoxaparin E. Acetylsalicylic acid

A, D. Heparin may be used during pregnancy because it does not cross the placental barrier and will not cause hemorrhage in the fetus. Enoxaparin does not cross the placental barrier; its classification for pregnancy is B. Clopidogrel is a platelet aggregation inhibitor. It is not used for thrombophlebitis; it is used to reduce the risk of brain attack, transient ischemic attack, unstable angina, and MI. Warfarin crosses the placental barrier, causing hemorrhage in the fetus. Acetylsalicylic acid is a platelet aggregation inhibitor and is not recommended during pregnancy (D category).

A pregnant client is prescribed heparin to prevent the risk of thromboembolism. Which adverse effects should the nurse anticipate with this medication? Select all that apply. A. Osteoporosis B. Suppress contractions in labor C. Increased risk of serious bleeding D. Stimulation of uterine contraction E. Compression fractures of the spine

A, E. Heparin is an anticoagulant. When heparin is taken concurrently during pregnancy, it may cause osteoporosis, which in turn can cause compression factures of the spine. The use of aspirin in the near term of pregnancy can suppress contractions in labor. The increased risk of serious bleeding also occurs with use of aspirin during pregnancy. The use of prostaglandin during pregnancy can cause stimulation of uterine contraction and can cause abortion.

A client is receiving warfarin. Which test result should the nurse use to determine whether the daily dose of this anticoagulant is therapeutic? A. International normalized ratio (INR) B. Accelerated partial thromboplastin time (aPTT) C. Bleeding time D. Sedimentation rate

A. Warfarin initially is prescribed day by day, based on INR blood test results. This test provides a standard system to interpret prothrombin times. APTT is used to evaluate the effects of heparin, which acts on the intrinsic pathway. Bleeding time is the time required for blood to cease flowing from a small wound; it is not used for warfarin dosage calculation. Sedimentation rate is a test used to determine the presence of inflammation or infection; it does not indicate clotting ability.

A HCP prescribes enoxaparin 30 mg subQ daily. Which measure would the nurse take when administering this medication? A. Push over 2 mins B. Administer in the abdomen C. Rub site after administration D. Remove air pocket from prepackaged syringe before administration

B. Enoxaparin specifically targets blood clots throughout the body and carries a lower risk of hemorrhage than that associated with the drugs heparin and warfarin. Enoxaparin is administered once a day through a subcutaneous injection site around the naval. Enoxaparin should be injected into the fatty tissue only, which is why the abdomen is the recommended injection site. Avoid administering in a muscle. Manufacturer recommendations indicate the air pocket from prepackaged syringes not be removed before administration. Rubbing the site is contraindicated, as it can cause bruising. There are no recommendations to push this subcutaneous medication over 2 mins.

After a DVT developed in a postpartum client, an IV infusion of heparin therapy was instituted 2 days ago. The client's activated partial thromboplastin time (aPTT) is now 98 seconds. What should the nurse do next? A. Increase the IV rate of heparin B. Interrupt the infusion and notify the PCP of the aPTT result C. Document the result on the medical record and recheck the aPTT in 4 hrs D. Call the PCP to obtain a prescription for a low-molecular-weight heparin

B. The heparin should be withheld, because 98 seconds is almost 3x the normal time it takes a fibrin clot to form (25 to 36 seconds), and prolonged bleeding may result; the therapeutic range for heparin is 1.5-2x the normal range. The PCP should be notified. The dosage of heparin must not be increased, because the client already has received too much. Documenting the result on the medical record and rechecking the aPTT in 4 hrs is an unsafe option. Continuing the infusion could result in hemorrhage. The medication does not have to be changed; it should be stopped temporarily until the aPTT is within the therapeutic range.

What should the nurse expect the HCP to prescribe if a client exhibits clinical indicators of warfarin overdose? A. Heparin B. Vitamin K C. Iron dextran D. Protamine sulfate

B. Warfarin depresses prothrombin activity and inhibits formation of several clotting factors by the liver. Its antagonist is vitamin K, which is involved in prothrombin formation. Heparin is an anticoagulant. Iron dextran is an iron supplement, not an antidote for warfarin. Protamine sulfate is the antidote for heparin overdose.

A client is started on a continuous infusion of heparin. Which finding does the nurse use to conclude that the intervention is therapeutic? A. International normalized ratio (INR) is between 2 and 3 B. Prothrombin time (PT) is 2.5x the control value C. Activated partial thromboplastin time (aPTT) is double the control value D. Activated clotting time (ACT) is in the range of 70 to 120

C. Activated partial thromboplastin time (aPTT) should be 1.5 to 2.5 for the control of heparin therapy. INR and PT are used to evaluate therapeutic levels of warfarin. The ACT increases to a range of 150 to 200 when heparin reaches therapeutic levels.

After teaching a family member how to administer subcutaneous enoxaparin sodium, how should a nurse evaluate the effectiveness of the training? A. Return demonstration on a manikin B. Verbalization of the side effects of the medication C. Observing the family member administering enoxaparin sodium to the client D. Correctly verbalizing all necessary steps in enoxaparin sodium administration

C. The best way to evaluate the effectiveness of the teaching is to observe the family member administering the medication to the client. The family member may be able to perform a subQ injection on a manikin but fear hurting the family member. Knowing the side effects of enoxaparin sodium is important, but it does not provide any information as to the family member's ability to administer the medication. The family member may be able to verbalize all the steps but fear puncturing the skin with the needle.

Warfarin is prescribed for a client who has been receiving IV heparin for a partial occlusion of the left common carotid artery. The client expresses concern about why both drugs are needed at the same time. What rationale does the nurse include to address the client's concern? A. This permits the administration of smaller doses of each medication B. Giving both drugs allows clot dissolution while preventing new clot formation C. Heparin provides anticoagulant effects until warfarin reaches therapeutic levels D. Administration of heparin with warfarin provides immediate and maximum protection against clot formation

C. Warfarin is administered orally for 2 to 3 days to achieve the desired effect on the international normalized ratio (INR) level before heparin is discontinued. These drugs do not dissolve clots already present. Because each drug affects a different part of the coagulation mechanism, dosages must be adjusted separately. That this approach immediately provides maximum protection against clot formation does not account for the reason for the administration of both drugs; warfarin will not exert an immediate therapeutic effect.

A client had a total knee replacement several days ago and has been receiving warfarin sodium therapy. An international normalized ratio (INR) is performed each afternoon, and the evening warfarin sodium dose is prescribed by the HCP on a daily basis. The nurse identifies that the afternoon INR is 4.6. Which is the next action the nurse should take? A. Assist with meal planning to decrease the intake of foods high in vitamin K B. Obtain a blood specimen to have a partial thromboplastin time performed C. Contact the HCP to request the day's dosage of warfarin sodium D. Maintain the client on bed rest until the HCP reviews the lab results

D. An INR of 4.6 is higher than the desired therapeutic level of 2 to 3.5. It is prudent to maintain bed rest to prevent injury until the HCP evaluates the client's INR result. Decreasing the intake of food high in vitamin K is contraindicated; vitamin K is the antidote for warfarin sodium. The client should have a consistent, limited intake of food high in vitamin K. A partial thromboplastin time (aPTT) is performed to evaluate a client's response to the administration of heparin. Another dose of warfarin sodium may be contraindicated in light of the client's increased INR result.

A client is admitted to the hospital with a diagnosis of DVT, and IV heparin sodium is prescribed. If the client experiences excessive bleeding, what should the nurse be prepared to administer? A. Vitamin K B. Oprelvekin C. Warfarin sodium D. Protamine sulfate

D. Protamine sulfate binds with heparin sodium to form a physiologically inert complex; it corrects clotting deficits. Vitamin K counteracts the effects of drugs like warfarin sodium (Coumadin). Oprelvekin is a thrombopoietic growth factor that stimulates the production of platelets. It would not be appropriate for emergency management. Warfarin sodium is an oral anticoagulant that interferes with the synthesis of prothrombin.

The HCP prescribes enoxaparin to be administered subcutaneously daily to a client who had a total knee replacement. To ensure client safety, which measure would the nurse take when administering this medication? A. Remove air pocket from prepackaged syringe before administration B. Rub the injection site after administration for 30 seconds C. Administer medication over 2 mins D. Administer in the abdomen area only

D. The preferred site for enoxaparin administration is the abdomen. According to package directions, the air pocket in the prepackaged syringe should not be removed. Rubbing the injection site also is contraindicated. Subcutaneous injections should not be given over 2 minutes.