ANTICOAGULATION COMPLETE SET OF CURRENT EXAM
QUESTIONS AND CORRECT ANSWERS
HL is taking Xarelto 15 mg PO twice daily at 9 AM and 9 PM for a newly
diagnosed deep vein thrombosis. HL calls the pharmacy at 4 PM and states that
he forgot to take his 9 AM dose of Xarelto. What should the pharmacist instruct
HL to do?
B. Take on 15mg tablet now and resume scheduled dosing at 9 PM tonight
Drug characteristics (eg, food requirements, dosing intervals, drug level timing)
are used to provide counseling on missed doses of medications. Incorrectly
taking a missed dose can cause harm or unintended consequences (eg, a
phosphate binder taken without food will not work). For most medications,
a missed dose should be taken as soon as the patient remembers, and doses
should not be doubled-up. Exceptions are oral contraceptive pills (missed doses
are occasionally doubled-up) and the initial venous thromboembolism (VTE)
dosing of rivaroxaban (Xarelto). Dosing of rivaroxaban for VTE is 15 mg PO
BID for 21 days, followed by 20 mg PO daily with missed doses taken as
follows:
15 mg tablet PO BID: Take the missed dose immediately. Two tablets may be
taken at the same time.
20 mg tablet PO once daily: Take the dose immediately. If it is already the next
day, skip the missed dose. Two 20 mg tablets should not be taken on the same
day.
(Choices A and D) One and a half rivaroxaban 15 mg tablets in a day will
result in a total dose of 22.5 mg. This is less than the required total daily dose of
30 mg.
,(Choices C and E) Taking one 15 mg rivaroxaban tablet per day to treat a
blood clot will not provide adequate anticoagulation.
Things to remember:Most missed doses should be taken as soon as the patient
remembers, and doses should not be doubled. The exceptions are oral
contraceptives and rivaroxaban (Xarelto) 15 mg PO twice daily, for which two
tablets may be taken simultaneously.
A 55-year-old male receives phytonadione 10 mg intravenously in the
emergency department. Which of the following adverse drug reactions should
the patient be monitored for?
D. Hypersensitivity reaction
Phytonadione (synthetic vitamin K) is used to reverse the effects of warfarin,
prevent/treat vitamin K deficiency, and treat coagulopathy in patients with liver
disease (off-label). Phytonadione acts as a cofactor to vitamin K–dependent
clotting factor synthesis, which replenishes endogenous clotting factors.
Intravenous and intramuscular administrations of phytonadione are generally
avoided due to safety concerns (boxed warning for hypersensitivity) but can be
given when other routes (eg, oral, subcutaneous) are not feasible or not
recommended. The hypersensitivity reaction from phytonadione (previously
called an anaphylactoid reaction) is IgE-independent and can result in cardiac
arrest. Strategies to minimize a hypersensitivity reaction include the following:
Dilute the drug in a minimum of 50 mL 0.9% sodium chloride or 5% dextrose.
Administer the lowest required dose at a slow rate, not to exceed 1 milligram
per minute.
(Choice A) Acute interstitial nephritis is a type of acute kidney injury
frequently associated with NSAIDs, proton pump inhibitors, and some
antibiotics (eg, aminoglycosides, amphotericin B), not phytonadione. It usually
occurs after repeated exposure (a few days later) to the offending drug.
(Choices B and E) Dystonia and neuroleptic malignant syndrome are
precipitated by antipsychotics, not phytonadione.
(Choice C) Hyperkalemia (high potassium) can be caused by many drugs,
including those that act on the renin-angiotensin-aldosterone system (eg, ACE
inhibitors) and potassium-sparing diuretics. Phytonadione is not associated with
hyperkalemia.
Things to remember:Due to the risk of hypersensitivity reactions, intravenous
phytonadione is reserved for situations when other routes of administration are
,not feasible or not recommended. To mimimize the risk of a hypersensitivity
reaction, the drug must be diluted in a minimum of 50 mL and administered at a
slow rate, not to exceed 1 milligram per minute.
A pharmacy technician trainee is preparing a batch of heparin bags based on the
standard compounding formula provided below.
During final verification, the pharmacist notices that 25 mL of unfractionated
heparin 10,000 units/mL was used while compounding. Which of the following
would most likely occur if this bag of heparin is administered to a patient?
C. Supratherapeutic activated partial thromboplastin time leading to an
increased risk of bleeding.
Anticoagulants [eg, unfractionated heparin (UFH)] are considered high-risk
medications because they can cause serious patient harm or death when used
in error. Safeguards should be in place throughout the medication process (eg,
ordering, compounding, delivery, administration) to minimize this risk. UFH
has many commercially available concentrations with nearly identical
packaging that are used in different settings (eg, heparin lock flush versus
heparin for systemic anticoagulation). Pharmacists must pay attention to drug
concentrations when compounding because of the impact an error can have on
the patient.
Routine monitoring of UFH with an activated partial thromboplastin time
(aPTT) is one way to ensure that the patient is safely and effectively
anticoagulated; an aPTT above the target range indicates a patient is receiving
too much anticoagulation. Administration of a heparin product that contains 10
times the expected amount of UFH would over-anticoagulate the patient and
increase the risk of a serious bleeding event (eg, intracranial hemorrhage).
(Choices A and B) A subtherapeutic aPTT (in a patient on anticoagulation)
occurs when the patient is not receiving enough anticoagulation; this increases
the risk of clotting, not bleeding.
(Choice D) A supratherapeutic aPTT indicates over-anticoagulation; this
increases the risk of bleeding, not clotting.
(Choice E) A patient will have a therapeutic aPTT when properly
anticoagulated; this is the expected outcome when the correct concentration of
UFH (10,000 units/10 mL) is used during compounding and administered to the
patient.
, Things to remember:Anticoagulants (eg, unfractionated heparin) are high-risk
medications that can lead to serious patient harm when used in error. Use of the
correct concentration during compounding and laboratory monitoring during
administration can decrease the risk of patient harm.
A 53-year-old female arrives at the emergency department with a severe
headache, vomiting, and muscle weakness. She is found to have a right
hemisphere hemorrhagic stroke.
Past Medical History: hypertension, obesity
Vital Signs: BP 185/105 mmHg, HR 110 bpm, RR 24 bpm, O2 sat 90% on
room air, T 100.4°F (38°C), Ht 5'9", Wt 130 kg
Laboratory Tests:Hemoglobin 12 g/dLHematocrit 36%Platelets 200,000
cells/mm3Serum creatinine 1.4 mg/dL
What is the best option to prevent a deep vein thrombosis in this patient during
the initial period of hospitalization?
E. Intermittent pneumatic compression devices
Pharmacists evaluate hospitalized patients on the need for venous
thromboembolism (VTE) prophylaxis. Hospital-acquired VTEs, including deep
vein thrombosis (DVT) and pulmonary embolism (PE), are preventable and can
occur in up to 15% of patients within the first 30 days following an acute stroke
(ischemic or hemorrhagic), with the peak incidence occurring in 2–7 days.
Pharmacologic DVT prophylaxis is contraindicated immediately following
a hemorrhagic stroke due to the risk of exacerbating the bleed.
However, nonpharmacological DVT prophylaxis can be initiated immediately
with intermittent pneumatic compression (IPC) devices, sometimes called
sequential compression devices (SCDs). IPC devices are sleeves or boots worn
over the legs that increase blood flow by periodically filling with air to apply
pressure on the legs. Initiating IPC devices within 72 hours of an acute stroke
can prevent DVT.
(Choice A) Aspirin is an antiplatelet drug that is started within 48 hours
following an ischemic stroke for secondary stroke prophylaxis. Aspirin
monotherapy is not adequate to prevent DVT.
(Choices B, C, and D) Pharmacologic DVT prophylaxis with subcutaneous
(SC) low molecular weight heparin (LMWH) or unfractionated heparin is
considered in a stable patient 1–4 days following hemorrhagic stroke. The
following doses are appropriate for DVT prophylaxis in this patient:
QUESTIONS AND CORRECT ANSWERS
HL is taking Xarelto 15 mg PO twice daily at 9 AM and 9 PM for a newly
diagnosed deep vein thrombosis. HL calls the pharmacy at 4 PM and states that
he forgot to take his 9 AM dose of Xarelto. What should the pharmacist instruct
HL to do?
B. Take on 15mg tablet now and resume scheduled dosing at 9 PM tonight
Drug characteristics (eg, food requirements, dosing intervals, drug level timing)
are used to provide counseling on missed doses of medications. Incorrectly
taking a missed dose can cause harm or unintended consequences (eg, a
phosphate binder taken without food will not work). For most medications,
a missed dose should be taken as soon as the patient remembers, and doses
should not be doubled-up. Exceptions are oral contraceptive pills (missed doses
are occasionally doubled-up) and the initial venous thromboembolism (VTE)
dosing of rivaroxaban (Xarelto). Dosing of rivaroxaban for VTE is 15 mg PO
BID for 21 days, followed by 20 mg PO daily with missed doses taken as
follows:
15 mg tablet PO BID: Take the missed dose immediately. Two tablets may be
taken at the same time.
20 mg tablet PO once daily: Take the dose immediately. If it is already the next
day, skip the missed dose. Two 20 mg tablets should not be taken on the same
day.
(Choices A and D) One and a half rivaroxaban 15 mg tablets in a day will
result in a total dose of 22.5 mg. This is less than the required total daily dose of
30 mg.
,(Choices C and E) Taking one 15 mg rivaroxaban tablet per day to treat a
blood clot will not provide adequate anticoagulation.
Things to remember:Most missed doses should be taken as soon as the patient
remembers, and doses should not be doubled. The exceptions are oral
contraceptives and rivaroxaban (Xarelto) 15 mg PO twice daily, for which two
tablets may be taken simultaneously.
A 55-year-old male receives phytonadione 10 mg intravenously in the
emergency department. Which of the following adverse drug reactions should
the patient be monitored for?
D. Hypersensitivity reaction
Phytonadione (synthetic vitamin K) is used to reverse the effects of warfarin,
prevent/treat vitamin K deficiency, and treat coagulopathy in patients with liver
disease (off-label). Phytonadione acts as a cofactor to vitamin K–dependent
clotting factor synthesis, which replenishes endogenous clotting factors.
Intravenous and intramuscular administrations of phytonadione are generally
avoided due to safety concerns (boxed warning for hypersensitivity) but can be
given when other routes (eg, oral, subcutaneous) are not feasible or not
recommended. The hypersensitivity reaction from phytonadione (previously
called an anaphylactoid reaction) is IgE-independent and can result in cardiac
arrest. Strategies to minimize a hypersensitivity reaction include the following:
Dilute the drug in a minimum of 50 mL 0.9% sodium chloride or 5% dextrose.
Administer the lowest required dose at a slow rate, not to exceed 1 milligram
per minute.
(Choice A) Acute interstitial nephritis is a type of acute kidney injury
frequently associated with NSAIDs, proton pump inhibitors, and some
antibiotics (eg, aminoglycosides, amphotericin B), not phytonadione. It usually
occurs after repeated exposure (a few days later) to the offending drug.
(Choices B and E) Dystonia and neuroleptic malignant syndrome are
precipitated by antipsychotics, not phytonadione.
(Choice C) Hyperkalemia (high potassium) can be caused by many drugs,
including those that act on the renin-angiotensin-aldosterone system (eg, ACE
inhibitors) and potassium-sparing diuretics. Phytonadione is not associated with
hyperkalemia.
Things to remember:Due to the risk of hypersensitivity reactions, intravenous
phytonadione is reserved for situations when other routes of administration are
,not feasible or not recommended. To mimimize the risk of a hypersensitivity
reaction, the drug must be diluted in a minimum of 50 mL and administered at a
slow rate, not to exceed 1 milligram per minute.
A pharmacy technician trainee is preparing a batch of heparin bags based on the
standard compounding formula provided below.
During final verification, the pharmacist notices that 25 mL of unfractionated
heparin 10,000 units/mL was used while compounding. Which of the following
would most likely occur if this bag of heparin is administered to a patient?
C. Supratherapeutic activated partial thromboplastin time leading to an
increased risk of bleeding.
Anticoagulants [eg, unfractionated heparin (UFH)] are considered high-risk
medications because they can cause serious patient harm or death when used
in error. Safeguards should be in place throughout the medication process (eg,
ordering, compounding, delivery, administration) to minimize this risk. UFH
has many commercially available concentrations with nearly identical
packaging that are used in different settings (eg, heparin lock flush versus
heparin for systemic anticoagulation). Pharmacists must pay attention to drug
concentrations when compounding because of the impact an error can have on
the patient.
Routine monitoring of UFH with an activated partial thromboplastin time
(aPTT) is one way to ensure that the patient is safely and effectively
anticoagulated; an aPTT above the target range indicates a patient is receiving
too much anticoagulation. Administration of a heparin product that contains 10
times the expected amount of UFH would over-anticoagulate the patient and
increase the risk of a serious bleeding event (eg, intracranial hemorrhage).
(Choices A and B) A subtherapeutic aPTT (in a patient on anticoagulation)
occurs when the patient is not receiving enough anticoagulation; this increases
the risk of clotting, not bleeding.
(Choice D) A supratherapeutic aPTT indicates over-anticoagulation; this
increases the risk of bleeding, not clotting.
(Choice E) A patient will have a therapeutic aPTT when properly
anticoagulated; this is the expected outcome when the correct concentration of
UFH (10,000 units/10 mL) is used during compounding and administered to the
patient.
, Things to remember:Anticoagulants (eg, unfractionated heparin) are high-risk
medications that can lead to serious patient harm when used in error. Use of the
correct concentration during compounding and laboratory monitoring during
administration can decrease the risk of patient harm.
A 53-year-old female arrives at the emergency department with a severe
headache, vomiting, and muscle weakness. She is found to have a right
hemisphere hemorrhagic stroke.
Past Medical History: hypertension, obesity
Vital Signs: BP 185/105 mmHg, HR 110 bpm, RR 24 bpm, O2 sat 90% on
room air, T 100.4°F (38°C), Ht 5'9", Wt 130 kg
Laboratory Tests:Hemoglobin 12 g/dLHematocrit 36%Platelets 200,000
cells/mm3Serum creatinine 1.4 mg/dL
What is the best option to prevent a deep vein thrombosis in this patient during
the initial period of hospitalization?
E. Intermittent pneumatic compression devices
Pharmacists evaluate hospitalized patients on the need for venous
thromboembolism (VTE) prophylaxis. Hospital-acquired VTEs, including deep
vein thrombosis (DVT) and pulmonary embolism (PE), are preventable and can
occur in up to 15% of patients within the first 30 days following an acute stroke
(ischemic or hemorrhagic), with the peak incidence occurring in 2–7 days.
Pharmacologic DVT prophylaxis is contraindicated immediately following
a hemorrhagic stroke due to the risk of exacerbating the bleed.
However, nonpharmacological DVT prophylaxis can be initiated immediately
with intermittent pneumatic compression (IPC) devices, sometimes called
sequential compression devices (SCDs). IPC devices are sleeves or boots worn
over the legs that increase blood flow by periodically filling with air to apply
pressure on the legs. Initiating IPC devices within 72 hours of an acute stroke
can prevent DVT.
(Choice A) Aspirin is an antiplatelet drug that is started within 48 hours
following an ischemic stroke for secondary stroke prophylaxis. Aspirin
monotherapy is not adequate to prevent DVT.
(Choices B, C, and D) Pharmacologic DVT prophylaxis with subcutaneous
(SC) low molecular weight heparin (LMWH) or unfractionated heparin is
considered in a stable patient 1–4 days following hemorrhagic stroke. The
following doses are appropriate for DVT prophylaxis in this patient:
