NR567
Final
Exam
Study
Guide
, NR567 Final Exam Study
Guide
Therapeutic dosing and monitoring of warfarin (Coumadin) & Types of anticoagulants- mechanisms of action and indications for use
Blood coagulation mechanisms:
1. injury exposes subendothelial matrix proteins (i.e. collagen and von Willebrand factor) result in platelet adherence and
activation, secretion and synthesis of vasoconstrictors and platelet-recruiting and activating molecules [thromboxane A2 is synthesized from
acid within platelets; platelets secrete ADP (a platelet aggregator) and serotonin (stimulates aggregation and vasoconstriction)] = platelet
plug
2. Coagulation system cascade is activated resulting in thrombin generation and a fibrin clot, which stabilizes the platelet plug
*1 & 2 occur simultaneously.
Indirect Thrombin MOA Dosage Monitoring Clinical Applications Toxicities & Reversal
Inhibitors
Unfractionated heparin 1. Binds to Continuous IV Activated partial Bleeding, hair loss, HIT
(UFH, HMW) antithrombin and infusion bolus: 80- thromboplastin time (heparin induced
inhibits clotting factor 100 units/kg followed (aPTT or PTT), CBC w/ thrombocytopenia)
proteases thrombin, by 15-22 units/kg per platelet count Long-term: osteoporosis,
IXa, and Xa hour spontaneous fractures,
Low dose mineralocorticoid
prophylaxis: 5000 deficiency
units subq Q8- 12h Protamine Sulfate: for
every 100 units heparin
remaining in patient,
1mg protamine sulfate
given
IV
Low-Molecular-Weight 1. Binds to Prophylactic: 30-40mg 1mg protamine sulfate
Heparin antithrombin and Q or BID Unnecessary may partially neutralize
Enoxaparin/Lovenox inhibits clotting factor Full dose: 1mg/kg 1 mg enoxaparin
Dalteparin proteases thrombin subq Q12h
Tinzaparin and Xa
, Fondaparinux 1. binds antithrombin, Once daily, subq Unnecessary No reversal agent
inhibiting factor Xa
Warfarin MOA Dosage Monitoring Clinical Applications Toxicities & Reversal
Warfarin/Coumadin 1. blockade of 5-10mg, usually 5- Prothrombin time Teratogenic effects
, gamma-carboxylation 7mg/d (PT) and INR PO/IV Vitamin K1, FFP,
resulting in Education: increased INR gaal:2-3 prothrombin complex
incomplete vitamin K intake INR goal w/ artificial concentrates (KCentra)
coagulation of factor (leafy greens) reduce heart valves: 2.5-
molecules that are anticoagulant effect 3.5
inactive of warfarin
Oral Direct Factor Xa MOA Dosage Monitoring Clinical Applications Toxicities & Reversal
Inhibitors
(aka DOAC)
Rivaroxaban/Xarelto 1. inhibit factor Xa Rivaroxaban: Unnecessary Rivaroxaban:
Apixaban/Eliquis prophylactic dose -stroke prevention in
Edoxaban post hip surgery: patients w/ afib w/o
10mg PO x35d vascular heart disease
prophylactic dose post
-prevention of VTE
knee surgery: 10mg
following hip/knee
PO x12d
DVT/PE tx: 15mg BID surgery
x3wk, then 20mg -VTE treatment
QD x3-6mon
Apixaban:
Apixaban: -stroke prevention in
prophylactic dose patients w/ afib w/o
post hip surgery: vascular heart disease
2.5mg PO BID x35d -prevention of VTE
prophylactic dose post following hip/knee
knee surgery: 2.5mg surgery
PO BID x12d
-VTE treatment
DVT/PE tx: 10mg BID
x3wk, then 5mg BID
x3- 6mon Edoxaban:
- stroke prevention in
Edoxaban: VTE/afib tx: patients w/ afib w/o
60mg QD vascular heart disease
-VTE treatment
following heparin tx
Final
Exam
Study
Guide
, NR567 Final Exam Study
Guide
Therapeutic dosing and monitoring of warfarin (Coumadin) & Types of anticoagulants- mechanisms of action and indications for use
Blood coagulation mechanisms:
1. injury exposes subendothelial matrix proteins (i.e. collagen and von Willebrand factor) result in platelet adherence and
activation, secretion and synthesis of vasoconstrictors and platelet-recruiting and activating molecules [thromboxane A2 is synthesized from
acid within platelets; platelets secrete ADP (a platelet aggregator) and serotonin (stimulates aggregation and vasoconstriction)] = platelet
plug
2. Coagulation system cascade is activated resulting in thrombin generation and a fibrin clot, which stabilizes the platelet plug
*1 & 2 occur simultaneously.
Indirect Thrombin MOA Dosage Monitoring Clinical Applications Toxicities & Reversal
Inhibitors
Unfractionated heparin 1. Binds to Continuous IV Activated partial Bleeding, hair loss, HIT
(UFH, HMW) antithrombin and infusion bolus: 80- thromboplastin time (heparin induced
inhibits clotting factor 100 units/kg followed (aPTT or PTT), CBC w/ thrombocytopenia)
proteases thrombin, by 15-22 units/kg per platelet count Long-term: osteoporosis,
IXa, and Xa hour spontaneous fractures,
Low dose mineralocorticoid
prophylaxis: 5000 deficiency
units subq Q8- 12h Protamine Sulfate: for
every 100 units heparin
remaining in patient,
1mg protamine sulfate
given
IV
Low-Molecular-Weight 1. Binds to Prophylactic: 30-40mg 1mg protamine sulfate
Heparin antithrombin and Q or BID Unnecessary may partially neutralize
Enoxaparin/Lovenox inhibits clotting factor Full dose: 1mg/kg 1 mg enoxaparin
Dalteparin proteases thrombin subq Q12h
Tinzaparin and Xa
, Fondaparinux 1. binds antithrombin, Once daily, subq Unnecessary No reversal agent
inhibiting factor Xa
Warfarin MOA Dosage Monitoring Clinical Applications Toxicities & Reversal
Warfarin/Coumadin 1. blockade of 5-10mg, usually 5- Prothrombin time Teratogenic effects
, gamma-carboxylation 7mg/d (PT) and INR PO/IV Vitamin K1, FFP,
resulting in Education: increased INR gaal:2-3 prothrombin complex
incomplete vitamin K intake INR goal w/ artificial concentrates (KCentra)
coagulation of factor (leafy greens) reduce heart valves: 2.5-
molecules that are anticoagulant effect 3.5
inactive of warfarin
Oral Direct Factor Xa MOA Dosage Monitoring Clinical Applications Toxicities & Reversal
Inhibitors
(aka DOAC)
Rivaroxaban/Xarelto 1. inhibit factor Xa Rivaroxaban: Unnecessary Rivaroxaban:
Apixaban/Eliquis prophylactic dose -stroke prevention in
Edoxaban post hip surgery: patients w/ afib w/o
10mg PO x35d vascular heart disease
prophylactic dose post
-prevention of VTE
knee surgery: 10mg
following hip/knee
PO x12d
DVT/PE tx: 15mg BID surgery
x3wk, then 20mg -VTE treatment
QD x3-6mon
Apixaban:
Apixaban: -stroke prevention in
prophylactic dose patients w/ afib w/o
post hip surgery: vascular heart disease
2.5mg PO BID x35d -prevention of VTE
prophylactic dose post following hip/knee
knee surgery: 2.5mg surgery
PO BID x12d
-VTE treatment
DVT/PE tx: 10mg BID
x3wk, then 5mg BID
x3- 6mon Edoxaban:
- stroke prevention in
Edoxaban: VTE/afib tx: patients w/ afib w/o
60mg QD vascular heart disease
-VTE treatment
following heparin tx
