NR 566 Week 5 Study Outline
Many questions are written to assess your clinical application of
the material from the textbook, in real-world scenarios.
Chapter 18: Drugs Affecting the Hematopoietic System
• Know the pharmacodynamics, pharmacotherapeutics
clinical use, drug interactions and adverse drug
reactions for:
• o Anticoagulants
• Pharmacodynamics Oral anticoagulants such as
warfarin (Coumadin) inhibit the hepatic synthesis of
several clotting factors, including factor X. The
decline in clotting factors is a function of the half-
life of each factor, which varies from 5 hours for
factor VII to 72 hours for factor II.
• Heparin inhibits the activity of several activated
clotting factors by accelerating the activity of
antithrombin III. LMWH enoxaparin (Lovenox)
potentiates the activity of antithrombin III and
inactivates factors Xa and IIa (thrombin). Dabigatran
(Pradaxa) is a direct thrombin inhibitor. Thrombin is
required for the conversion of fibrinogen to fibrin in
the clotting cascade, thus dabigatran's inhibition of
thrombin prevents thrombi from forming.
Fondaparinux (Arixtra) is a selective inhibitor of
antithrombin III and a factor Xa inhibitor. An
anticoagulant, rivaroxaban (Xarelto), is a highly
selective factor Xa inhibitor that inhibits thrombin
formation and the development of thrombi. Apixaban
(Eliquis) is a selective inhibitor of factor Xa.
• Aspirin antagonizes the cyclooxygenase pathway
and interferes with platelet aggregation. NSAIDs have
this
, same action. NSAIDs are not used as antiplatelet
drugs, but this explains why concurrent use with
anticoagulants is contraindicated
• Ticlopidine (Ticlid) and clopidogrel (Plavix) reduce
platelet aggregation by inhibiting the ADP pathway of
platelets. Unlike aspirin, they have no effect on
prostaglandin metabolism. Ticagrelor (Brilinta)
reversibly interacts with the platelet P2Y12 ADP-
receptor to prevent platelet activation. Vorapaxar
(Zontivity) is a protease-activated receptor-1 (PAR-1)
antagonist, inhibiting thrombin-induced and thrombin
receptor agonist peptide-induced platelet
aggregation
• Precautions and Contraindications All
anticoagulants are contraindicated for patients who
are hypersensitive to the drug or actively bleeding or
who have hemophilia, thrombocytopenia, severe
hypertension (HTN), intracranial hemorrhage,
infective endocarditis, active tuberculosis, or
ulcerative lesions of the GI tract. Heparins are
contraindicated in advanced hepatic or renal disease.
They may be used in patients who are actively
bleeding to treat disseminated intravascular
coagulation (DIC). Heparin is Pregnancy Category
C.
• LMWHs are contraindicated for patients with
allergies to pork, sulfites, or benzyl alcohol;
uncontrolled bleeding; and in patients who have
antiplatelet antibodies.
Use caution in hepatic dysfunction and use of warfarin and increased
risk of bleeding with adults
Warfarin crosses the placenta and can cause
hemorrhagic disorders in the fetus and serious birth
, defects. It is Pregnancy Category X and should not be
administered during pregnancy.
Rivaroxaban (Xarelto) was given a Black-Box Warning in
August 2013 indicating the premature discontinuation of
anticoagulants including rivaroxaban may lead to
thrombotic events. An increased risk of stroke is seen in
patients with atrial fibrillation when transitioning to
warfarin. Rivaroxaban is Pregnancy Category C and is not
recommended for use in pregnant women. Apixaban
(Eliquis) was given a similar Black Box warning regarding
premature discontinuation leading to thrombotic events
when it was approved. Although there are no well-
controlled studies, apixaban is Pregnancy Category B.
Hypersensitivity to aspirin and cross-sensitivity with
NSAIDs may occur, contraindicating the drug. Aspirin
hypersensitivity is more prevalent in patients with
asthma, nasal polyps, or chronic urticaria. Reye syndrome
has been associated with its use in children and
teenagers who have influenza or chickenpox. Reversible
hepatotoxicity has occurred.
Ticagrelor has a Black-Box Warning to not use in a patient
with active pathological bleeding or history of intracranial
hemorrhage. Ticagrelor should be discontinued 5 days
prior to any surgery.
Dabigatran has a Black-Box Warning concerning
discontinuation increasing risk of thrombotic events.
There is no reversal agent available for dabigatron if
excessive bleeding occurs.
Vorapaxar has a Black-Box Warning to not use in patients
with a history of stroke, transient ischemic attack (TIA),
intracranial hemorrhage, or active pathological bleeding.
Many questions are written to assess your clinical application of
the material from the textbook, in real-world scenarios.
Chapter 18: Drugs Affecting the Hematopoietic System
• Know the pharmacodynamics, pharmacotherapeutics
clinical use, drug interactions and adverse drug
reactions for:
• o Anticoagulants
• Pharmacodynamics Oral anticoagulants such as
warfarin (Coumadin) inhibit the hepatic synthesis of
several clotting factors, including factor X. The
decline in clotting factors is a function of the half-
life of each factor, which varies from 5 hours for
factor VII to 72 hours for factor II.
• Heparin inhibits the activity of several activated
clotting factors by accelerating the activity of
antithrombin III. LMWH enoxaparin (Lovenox)
potentiates the activity of antithrombin III and
inactivates factors Xa and IIa (thrombin). Dabigatran
(Pradaxa) is a direct thrombin inhibitor. Thrombin is
required for the conversion of fibrinogen to fibrin in
the clotting cascade, thus dabigatran's inhibition of
thrombin prevents thrombi from forming.
Fondaparinux (Arixtra) is a selective inhibitor of
antithrombin III and a factor Xa inhibitor. An
anticoagulant, rivaroxaban (Xarelto), is a highly
selective factor Xa inhibitor that inhibits thrombin
formation and the development of thrombi. Apixaban
(Eliquis) is a selective inhibitor of factor Xa.
• Aspirin antagonizes the cyclooxygenase pathway
and interferes with platelet aggregation. NSAIDs have
this
, same action. NSAIDs are not used as antiplatelet
drugs, but this explains why concurrent use with
anticoagulants is contraindicated
• Ticlopidine (Ticlid) and clopidogrel (Plavix) reduce
platelet aggregation by inhibiting the ADP pathway of
platelets. Unlike aspirin, they have no effect on
prostaglandin metabolism. Ticagrelor (Brilinta)
reversibly interacts with the platelet P2Y12 ADP-
receptor to prevent platelet activation. Vorapaxar
(Zontivity) is a protease-activated receptor-1 (PAR-1)
antagonist, inhibiting thrombin-induced and thrombin
receptor agonist peptide-induced platelet
aggregation
• Precautions and Contraindications All
anticoagulants are contraindicated for patients who
are hypersensitive to the drug or actively bleeding or
who have hemophilia, thrombocytopenia, severe
hypertension (HTN), intracranial hemorrhage,
infective endocarditis, active tuberculosis, or
ulcerative lesions of the GI tract. Heparins are
contraindicated in advanced hepatic or renal disease.
They may be used in patients who are actively
bleeding to treat disseminated intravascular
coagulation (DIC). Heparin is Pregnancy Category
C.
• LMWHs are contraindicated for patients with
allergies to pork, sulfites, or benzyl alcohol;
uncontrolled bleeding; and in patients who have
antiplatelet antibodies.
Use caution in hepatic dysfunction and use of warfarin and increased
risk of bleeding with adults
Warfarin crosses the placenta and can cause
hemorrhagic disorders in the fetus and serious birth
, defects. It is Pregnancy Category X and should not be
administered during pregnancy.
Rivaroxaban (Xarelto) was given a Black-Box Warning in
August 2013 indicating the premature discontinuation of
anticoagulants including rivaroxaban may lead to
thrombotic events. An increased risk of stroke is seen in
patients with atrial fibrillation when transitioning to
warfarin. Rivaroxaban is Pregnancy Category C and is not
recommended for use in pregnant women. Apixaban
(Eliquis) was given a similar Black Box warning regarding
premature discontinuation leading to thrombotic events
when it was approved. Although there are no well-
controlled studies, apixaban is Pregnancy Category B.
Hypersensitivity to aspirin and cross-sensitivity with
NSAIDs may occur, contraindicating the drug. Aspirin
hypersensitivity is more prevalent in patients with
asthma, nasal polyps, or chronic urticaria. Reye syndrome
has been associated with its use in children and
teenagers who have influenza or chickenpox. Reversible
hepatotoxicity has occurred.
Ticagrelor has a Black-Box Warning to not use in a patient
with active pathological bleeding or history of intracranial
hemorrhage. Ticagrelor should be discontinued 5 days
prior to any surgery.
Dabigatran has a Black-Box Warning concerning
discontinuation increasing risk of thrombotic events.
There is no reversal agent available for dabigatron if
excessive bleeding occurs.
Vorapaxar has a Black-Box Warning to not use in patients
with a history of stroke, transient ischemic attack (TIA),
intracranial hemorrhage, or active pathological bleeding.
