Anticoagulation 1 – Flashcards
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Karla Porter is a 58 year-old female who is usually well-controlled on a warfarin regimen of 5 mg daily. She has been sick for the past week but feels better today. She ate little during her illness. Ms. Porter presents to the anticoagulation clinic to have her INR checked. Her INR is elevated today at 5.8. There is no noticeable bleeding and she is a low bleeding risk. Choose the preferred course of action:
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B) Omit the next few doses, monitor frequently, and resume therapy at a lower dose when the INR is in the therapeutic range. According to the CHEST 2012 guidelines, patients with a *supratherapeutic INR of 4.5 - 10 and without bleeding should not routinely receive vitamin K.* Therefore, the patient should have 1 - 2 doses of warfarin held and the INR monitored. Restart warfarin at a lower dose when the INR is in the therapeutic range.
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A hospitalized patient is post-op day #1 after a right hip arthroplasty. The patient has a history of a previous VTE. The doctor has recommended that the patient begin warfarin with Lovenox bridge therapy but the patient responds that he does not wish to take "rat poison". The pharmacy intern wants to explain to the patient the risks associated with not taking an anticoagulant, when indicated. The intern should explain to the patient that he is at higher risk for the following complications if he chooses not to use the warfarin: (Select ALL that apply.)
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A) Deep vein thrombosis B) Pulmonary embolism NOTE: The primary risks in this patient from not using anticoagulants or having anticoagulants at subtherapeutic levels are deep vein thrombosis (DVT) and/or pulmonary embolism (PE).
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Which of the following procedures can help reduce medication errors associated with heparin? (Select ALL that apply.)
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A) Do not use the color of the syringe or packaging to verify the dose. B) Provide inservices that review heparin safety, including the lower heparin flush concentrations to the higher treatment doses. C) If possible, outsource the preparation of heparin flushes. E) Have the pharmacist verify the heparin concentration for the patient's indication. Heparin as an anticoagulant that comes in different strengths. To help avoid errors, heparin should not be stocked in unfamiliar concentrations. The concentration must be verified by the pharmacist prior to dispensing the dose. The color of the bag or syringe should not be used to verify the dose. Having the pharmacy prepare the flush syringes (rather than busy unit nurses) can help reduce errors. Buying prepared heparin syringes (outsourcing) is most preferable.
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What would be expected to occur if a patient on warfarin with a stable INR is started on phenobarbital? (Select ALL that apply.)
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B) The INR would decrease. C) The patient may clot. Phenobarbital is a strong hepatic *enzyme inducer* and would lower the INR and put the patient at risk for clotting.
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Select the correct indication for dabigatran:
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B) To reduce the risk of stroke and blood clots in patients with non-valvular atrial fibrillation. Dabigatran (Pradaxa - direct Thrombin inhibitor) is indicated to reduce the risk of stroke and systemic embolism in patients with non-valvular atrial fibrillation, to treat DVT/PE, to reduce risk of recurrence of DVT/PE and for prophylaxis of DVT/PE following hip replacement surgery.
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A 70 year-old patient has been using warfarin therapy in the hospital. She had a deep vein thrombosis (DVT) in her right lower leg. She is being discharged, and the outpatient pharmacist who is going to dispense her warfarin is checking her medication profile for drug interactions. The pharmacist notes that the patient is using medications which increase the risk of bleeding. She will counsel the patient on increased bleeding risk. Which of the following medications can increase her bleeding risk? (Select ALL that apply.)
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B) Clopidogrel C) Amiodarone D) Ginkgo biloba Clopidogrel, amiodarone, and ginkgo biloba can increase the risk of bleeding in patients taking warfarin.
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Which of the following statements regarding warfarin are correct? (Select ALL that apply.)
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B) Warfarin blocks the activation of clotting factors II, VII, IX, and X. D) Warfarin is a vitamin K antagonist. Warfarin is a vitamin K antagonist. Vitamin K is required for the *carboxylation of clotting factors II, VII, IX, and X.* Without adequate vitamin K, the liver produces the factors, but they have reduced coagulant activity.
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Select the correct dosing recommendation for dabigatran for a patient with a DVT and a creatinine clearance of 54 mL/min: Pradaxa.
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C) Take a 150 mg capsule twice daily, with or without food. For patients with atrial fibrillation and *CrCl 15-30 mL/min, the recommended dose is 75 mg twice daily.* *Dabigatran is dosed BID* and it is important that patients remember to take both doses. The medication does not last long and if it is not taken appropriately, the patient is at risk of stroke. *Dabigatran is taken without regard to meals.*
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Muhammad Al-Hadeen is a 66 year-old male with hypertension, renal disease and degenerative joint disease. In his younger years, Mr. Al-Hadeen was a football player and has lived with the pain of a hip injury for many years. He enters the hospital for elective hip replacement surgery. His creatinine clearance is 25 mL/min. The physician orders enoxaparin 30 mg SC BID for DVT prophylaxis. Choose the correct statement:
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Ð’) The dose should be 30 mg SC daily. The physician ordered the correct prophylactic dose of enoxaparin for a patient without significant renal disease *(30 mg SC BID, or 40 mg SC daily)*. If the *creatinine clearance is less than 30 mL/min*, the dose is reduced to 30 mg SC once daily.
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Select the correct mechanism of action for Pradaxa:
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A) Oral direct Factor IIa inhibitor *IIa - thrombin*. Pradaxa is a direct thrombin inhibitor.
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Which of the following is a possible side effect from the long-term use of heparin therapy?
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B) Osteoporosis Osteoporosis can occur with long-term use. Women who are pregnant and are using heparin long-term are at risk for decreased bone density.
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Low molecular weight heparins have a boxed warning concerning this risk:
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B) *Spinal or epidural hematoma formation* The risk is highest if the patient receives *neuraxial anesthesia* or has a spinal puncture concurrently. These hematomas may result in long-term or permanent paralysis.
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A patient has developed a DVT and will be placed on dalteparin. Choose the correct statements concerning dalteparin:
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D) Dalteparin is monitored by anti-Xa levels but monitoring is not required in everyone. NOTE: Dalteparin is administered by subcutaneous (SC) injection and is contraindicated if the patient had a history of HIT. It is a LMWH.
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A new patient is using enoxaparin therapy for "bridging" until her INR level is therapeutic. She brings the following over-the-counter medicines to the pharmacy window for payment: DHEA, Women's 50+ multivitamin, Advil Migraine, coenzyme Q10 and a B-Complex vitamin. The pharmacist should offer the following advice:
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A) Advil Migraine is not safe to use with warfarin; acetaminophen is safer. NSAIDs, like Advil Migraine, do not raise the INR, but they do increase bleeding risk by an antiplatelet effect. Willow bark can increase the bleeding risk as well.
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What is the purpose of using a heparin "lock-flush," such as HepFlush?
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C) To keep IV lines open Heparin "lock-flushes" (HepFlush) are used to keep IV lines open (patent). They are not used for anticoagulation. There have been fatal errors made by choosing the incorrect heparin strength. Using a higher dose to flush a line could cause significant bleeding, including fatal hemorrhage. Many of the dosing errors have occurred in neonates.
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Chief Complaint: "I can't walk - it hurts so bad." Question: The physician plans to start Ms. Tirrell on *enoxaparin*, but would like to order a laboratory test to monitor efficacy of *enoxaparin* therapy. Which of the following could be recommended?
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C) *Peak anti-Xa*, 4 hours after the dose Routine monitoring of enoxaparin therapy with anti-Xa levels is not necessary, but monitoring can be done in certain patients. If anti-Xa levels are ordered, they should be drawn 4 hours after the SC dose (peak).
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Terry Lance was admitted to the local hospital for a knee replacement. Orthopedic surgery is considered high risk for venous thromboembolism (VTE) but TL did not receive any VTE prophylaxis. He developed a deep vein thrombosis and was discharged on warfarin. This was his first incidence of VTE. Normally, Mr. Lance is thin and active. How long should he receive warfarin?
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C) Three months This patient had an increased risk for VTE only due to the orthopedic surgery. He will need anticoagulation for three months.
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Vitamin K given IV has a risk of the following adverse reaction:
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D) Anaphylaxis The administration of vitamin K intravenously is associated with the risk of anaphylaxis (dyspnea, cardiac arrest, hypotension, shock).
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The pharmacist will counsel a patient on the correct self-administration technique for enoxaparin. Which of the following are correct counseling statements? (Select ALL that apply.)
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A) This medication can cause the patient to bruise and/or bleed more easily. B) Choose an area on the right or left side of the patient's abdomen, but not within two inches from the belly button. C) Do not expel the air bubble in the syringe prior to injection. NOTE: Do NOT expel the air bubble in the syringe as it can *cause the patient to get a subtherapeutic dose* because some of the medicine will be lost (as long as the exact dose needed is the amount in the syringe). With some medications it is recommended to rub the site after injection, but NOT with drugs that can cause bleeding, such as this one.
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Michael Gallagher is a 43 year-old male who is usually well-controlled on a warfarin regimen of 7.5 mg five days per week, and 5 mg two days weekly. He presents to the anticoagulation clinic to have his INR checked. He reports that he had an upper respiratory infection and the physician had given him a 10-day course of levofloxacin. He just took his last levofloxacin tablet this morning. His INR is elevated today at 3.5; the target therapeutic INR is 2-3. Choose the preferred course of action:
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A) Hold the warfarin dose today; resume usual dosing regimen when INR is therapeutic and have the patient monitor for symptoms of bleeding. Phytonadione is not recommended for *INR < 4.5.*
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What would be expected to occur if a patient on warfarin with a stable INR is started on fluconazole?
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B) The INR would increase and the patient may experience bleeding. Fluconazole inhibits the metabolism of warfarin (CYP2C9- main metabolizing enzyme inhibitor); therefore, increasing the INR and potentially causing the patient to bleed.
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A patient has developed a DVT and will be placed on dalteparin. What is the correct brand name for dalteparin?
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B) Fragmin Apixaban is Eliquis Fondaparinux is Arixtra Bivalirudin is Angiomax
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Hong Yu is a 58 year-old male with atrial fibrillation. He has been using warfarin for over two years and is normally well-controlled. His cardiologist recently began amiodarone and citalopram therapy with no other medication adjustments. He is admitted to the emergency room with weakness and bleeding gums. The INR is obtained and is 9.5. His hemoglobin is 8.4 g/dL. His pants are stained with blood which is coming from his rectum. Choose the correct course of action:
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D) Hold warfarin therapy and give vitamin K 10 mg by slow IV injection along with four-factor prothrombin complex concentrate. *Vitamin K + Kcentra (4F-PCC)* With major bleeding, vitamin K 10 mg should be given by slow IV injection along with *four-factor prothrombin complex concentrate*, which is preferred over fresh frozen plasma.
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Choose the correct antidote to use in the case of a heparin overdose:
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A) Protamine
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Which of the following organizations sets the guidelines for the management of antithrombotics?
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C) The American College of Chest Physicians (ACCP): Evidence-Based Clinical Practice Guidelines, published in the journal CHEST
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A female patient who is pregnant has been admitted to the hospital with a DVT. The physician will begin heparin therapy. What is the mechanism of action of heparin?
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D) Heparin potentiates antithrombin (anti-IIa)
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John Wu arrives at the clinic pharmacy with a prescription for apixaban 5 mg BID. He is 52 years old, 6'1" and weighs 214 lbs. His recent laboratory parameters include a Na 139 mEq/L and SCr of 1.1 mg/dL. At the clinic today, he was diagnosed with a DVT. Which of the following statements are correct regarding apixaban for this patient?
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E) Apixban carries a boxed warning regarding the risk of stroke in patients who discontinue therapy prematurely. Apixaban dosing *differs for each indication*. It can be taken *without regards to food*. Discontinuation of therapy without adequate anticoagulation with an alternative agent *increases the risk of stroke.*
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A 42 year-old female with a heart condition is presenting to the hospital with a DVT. The medical resident wishes to give her a low molecular weight heparin (LMWH), but the older supervising physician insists on using heparin. What are advantages to the use of LMWHs over heparin? (Select ALL that apply.)
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B) LMWHs are more cost effective than heparin. D) LMWHs do not require monitoring in some patients. E) LMWHs have a more consistent anticoagulation response. NOTE: Unlike heparin, LMWHs do not require monitoring in every patient. *Anti-factor Xa levels* can be monitored in select patients, but this is not necessary in most patients. LMWHs are more cost effective than heparin.
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A 25 year-old female is receiving warfarin for a DVT. Her counseling should include the following:
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E) Warfarin is unsafe in pregnancy and cannot be used (Pregnancy Category X) Warfarin is contraindicated in pregnancy (Pregnancy Category X) *unless the patient has a mechanical heart valve (Pregnancy Category D).*
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Rivaroxaban works by the following mechanism of action:
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B) Factor Xa inhibitor Rivaroxaban is an oral Factor Xa inhibitor.
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Judy Keith is a 62 year-old female with chronic urinary tract infections. Several times a year, she receives a prescription for Bactrim. The physician suggested she use the antibiotic daily, but she prefers not to because she feels that she is already using too many medications. Ms. Keith comes to the pharmacy today with a prescription for warfarin. She tells the pharmacist that the heart doctor found her heart was "beating funny." The pharmacist should emphasize the following counseling to Ms. Keith: (Select ALL that apply.)
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A) If she gets a UTI, the antibiotic Bactrim could make her *warfarin level increase.* C) The drug interaction between warfarin and Bactrim for a UTI may lead to *significant bleeding.* E) She should make sure to inform her health care providers that she is using warfarin so they can choose alternative medications that do not cause drug-drug interactions. NOTE: Bactrim can inhibit the metabolism of warfarin putting the patient at risk for bleeding. All providers treating Judy Keith should know she is taking warfarin to prevent drug-drug interactions.
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Select the correct mechanism of action for Lovenox:
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D) Inhibits Factor Xa and Factor IIa via antithrombin Lovenox is a low molecular weight heparin (LMWH). LMWHs work by binding to antithrombin which then inhibit clotting factors Xa and IIa. Enoxaparin binds to antithrombin (a circulating anticoagulant) to form a complex that irreversibly inactivates clotting factor Xa. It has less activity against factor IIa (thrombin) compared to unfractionated heparin (UFH) due to its low molecular weight.
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When heparin is administered, the following laboratory value must be carefully monitored:
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C) Platelets A serious adverse effect associated with heparin therapy is heparin-induced thrombocytopenia, or HIT. This is a significant drop in platelets caused by an immune response against platelets. Platelets must be monitored during therapy.
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A pharmacist working in an inpatient medical ward of the local hospital is responsible for monitoring anticoagulation therapy. She routinely obtains laboratory parameters and adjusts the doses of low molecular weight heparins (LMWHs), as needed. In which of the following clinical situations is it appropriate to monitor the level of anticoagulation with LMWH therapy? (Select ALL that apply.)
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B) Significant renal impairment C) Pregnant patient with PE D) Pregnant patient with mechanical heart valves E) Extremes of body weight Weight, renal function, pregnancy
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What would be expected to occur if a patient on warfarin with a stable INR is started on amiodarone?
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C) The INR would increase and the patient may experience bleeding. Amiodarone *inhibits the metabolism of warfarin*; therefore, increasing the INR and potentially causing the patient to bleed.
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A patient has developed heparin-induced thrombocytopenia (HIT). He requires anticoagulation therapy for a pulmonary embolism. Which of the following agents would not pose a risk for HIT in this patient?
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B) Argatroban Argatroban is FDA approved for use in HIT and is recommended first-line by the CHEST guidelines.
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By what routes of administration can heparin be given?
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E) Intravenous and subcutaneous administration Heparin is administered by IV or SC injection. Heparin is *NOT administered by IM injection* due to pain and the risk of hematoma formation. Heparin is *NOT bioavailable via the oral route.*
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Which of the following groups of laboratory parameters need to be monitored during heparin therapy?
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D) Hematocrit, hemoglobin, platelets, and aPTT Hematocrit, hemoglobin, platelets, and aPTT are important laboratory parameters to monitor while a patient is receiving heparin therapy.
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A hospitalized patient developed a pulmonary embolism and was started on enoxaparin therapy. The physician began warfarin therapy on Monday and wrote an order to discontinue the enoxaparin therapy the following day. The pharmacist contacted the prescriber to recommend the following action:
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B) Continue the enoxaparin until the INR has been therapeutic for at least 24 hours. Continuation of the parenteral anticoagulant should occur for a *minimum of 5 days and until the INR is therapeutic (INR at 2.0 or above in this scenario) for at least 24 hours*
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Henry Wong is receiving a heparin drip. What is the name of the test used to monitor heparin for efficacy?
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E) *The activated partial thromboplastin time* The activated partial thromboplastin time (aPTT) is used to monitor the effect of heparin. The aPTT is the time, in seconds, for plasma to clot. A normal aPTT is generally between 22-38 seconds. The therapeutic aPTT range is determined individually for each hospital or laboratory depending on the reagent.
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Patients may use the following non-pharmacological method to reduce the risk of venous thromboembolism:
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D) Use intermittent pneumatic compression devices. Graduated compression stockings (GCS) and intermittent pneumatic compression (IPC) devices are two non-pharmacologic measures used to prevent venous thromboembolism.
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A patient is being started on Pradaxa. Choose the correct statement regarding Pradaxa:
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D) Once a bottle of Pradaxa is opened, the capsules must be used within 120 days.
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Which of the following is the most likely adverse effect from the use of heparin?
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C) Bleeding
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Why is it important for hospitals to get INRs taken at about the same time in the morning?
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C) Healthcare providers will have the INR value and be able to adjust that day's warfarin dose. Warfarin is generally dosed in the late afternoon or evening. If the INR is taken earlier in the day, the warfarin dose can still be adjusted prior to administration. Or, if the INR is elevated, the warfarin can be held.
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Adriana Guardia is beginning warfarin therapy. She asks the pharmacist which foods are high in vitamin K. Which of the following foods are high in vitamin K? (Select ALL that apply.)
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A) Cauliflower B) Canola and soybean oils C) Broccoli and brussels sprouts E) Green and black tea
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Chief Complaint: "I can't walk - it hurts so bad." Question: Ms. Tirrell's healthcare provider would like to start warfarin per the Anticoagulation Management protocol at the hospital. Which of the following is appropriate to start along with warfarin on day #1 of therapy for the DVT?
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E) *Lovenox 90 mg SC Q12H* Warfarin should be started on the same day as a parenteral anticoagulant (LMWH or UFH) for DVT/PE. The parenteral anticoagulant must be used in a treatment dose, not a prophylactic dose.
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In which of the following scenarios are the intravenous direct thrombin inhibitors considered the drugs of choice?
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A) To provide anticoagulation in patients who have heparin-induced thrombocytopenia (HIT). Direct thrombin inhibitors have been very important clinically since they *do NOT cross-react with heparin-induced thrombocytopenia (HIT) antibodies.* Once HIT develops, the injectable direct thrombin inhibitors are the drugs of choice.
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Chief Complaint: "I can't walk - it hurts so bad." Question: On day #6 of the hospitalization, Ms. Tirrell is doing better. Her chronic conditions are under better control. She mentions to the case manager that she lives almost 2 hours from town and has no transportation to come to the clinic for labs or office visits. The physician would like to discharge Ms. Tirrell on an *oral anticoagulant* that does not require laboratory monitoring. Which of the following are options for Ms. Tirrell? (Select ALL that apply.)
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B) Pradaxa D) Xarelto E) Eliquis
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Select the correct statement concerning Pradaxa:
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E) It does not require blood testing to monitor for effectiveness. Pradaxa is indicated for *non-valvular atrial fibrillation* and it does not require blood tests to monitor for effectiveness. Pradaxa causes *MORE GI bleeds than warfarin.*
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What is the name of the test used to monitor warfarin efficacy and toxicity?
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D) The international normalized ratio
