NR 567 Week 8 Final Exam Study Guide

Institution	NR 567 Advanced Pharmacology for the Adult-Gerontology Acute Care Nurse
Contributor	Jaime Bradely

Therapeutic dosing and monitoring of warfarin (Coumadin) & Types of anticoagulants- mechanisms of action and indications for use

Blood coagulation mechanisms:

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
Coagulation system cascade is activated resulting in thrombin generation and a fibrin clot, which stabilizes the platelet plug

*1 & 2 occur simultaneously.

Indirect Thrombin Inhibitors	MOA	Dosage	Monitoring	Clinical Applications	Toxicities & Reversal
Unfractionated heparin (UFH, HMW)	1. Binds to antithrombin and inhibits clotting factor proteases thrombin, IXa, and Xa	Continuous IV infusion bolus: 80-100 units/kg followed by 15-22 units/kg per hour Low dose prophylaxis: 5000 units subq Q8- 12h	Activated partial thromboplastin time (aPTT or PTT), CBC w/ platelet count		Bleeding, hair loss, HIT (heparin induced thrombocytopenia) Long-term: osteoporosis, spontaneous fractures, mineralocorticoid deficiency Protamine Sulfate: for every 100 units heparin remaining in patient, 1mg protamine sulfate given IV
Low-Molecular-Weight Heparin Enoxaparin/Lovenox Dalteparin Tinzaparin	1. Binds to antithrombin and inhibits clotting factor proteases thrombin and Xa	Prophylactic: 30-40mg Q or BID Full dose: 1mg/kg subq Q12h	Unnecessary		1mg protamine sulfate may partially neutralize 1 mg enoxaparin
Fondaparinux	1. binds antithrombin, inhibiting factor Xa	Once daily, subq	Unnecessary		No reversal agent

Warfarin	MOA	Dosage	Monitoring	Clinical Applications	Toxicities & Reversal
Warfarin/Coumadin	1. blockade of	5-10mg, usually 5-	Prothrombin time		Teratogenic effects

gamma-carboxylation resulting in incomplete coagulation of factor molecules that are

inactive

7mg/d

Education: increased vitamin K intake (leafy greens) reduce anticoagulant effect

of warfarin

(PT) and INR INR gaal:2-3

INR goal w/ artificial heart valves: 2.5-3.5

PO/IV Vitamin K1, FFP, prothrombin complex concentrates (KCentra)

Instituition / Term
Term	Year 2022
Institution	NR 567 Advanced Pharmacology for the Adult-Gerontology Acute Care Nurse
Contributor	Jaime Bradely