Test 2 Anticoagulants

Question 1

argatroban: class

Answer 1

• anticoagulant
• direct thrombin inhibitor

Question 2

argatroban: MOA

Answer 2

• directly inhibits thrombin
  
  • Inhibition of thrombin prevents activation of factors V, VIII, and XII; the conversion of fibrinogen to fibrin; platelet adhesion and aggregation.

Question 3

argatroban: indications

Answer 3

• prophylaxis and tx of thrombosis in pts with HIT

Question 4

argatroban: SEs

Answer 4

• dyspnea
• cough
• rash

Question 5

argatroban: ADRs

Answer 5

• bleeding
• anaphylaxis

Question 6

argatroban: nursing implications

Answer 6

• monitor treatment by measuring aPTT
• short half life b/c of rapid metabolism by liver
• only give thru IV
• watch BP: if unexplained hypoTN, look for bleeding

Question 7

bivalirudin: class

Answer 7

• hirudin analog
• direct thrombin inhibitor

Question 8

bivalirudin: MOA

Answer 8

• direct, reversible inhibitor of thrombin
• drug binds with and inhibits thrombin that is free in the blood as well as thrombin that is bound to clots
  
  • prevents conversion of fibrinogen to fibrin
  • prevents activation of factor XIII, so it prevents conversion of soluble fibrin into insoluble fibrin

Question 9

bivalirudin: indications

Answer 9

• given in combination with aspirin, clopidogrel, or prasugrel to prevent clot formation in pts undergoing coronary angioplasty
• prevents ischemic complications
  
  • MI, abrupt vessel closure, death

Question 10

bivalirudin and heparin

Answer 10

• bivalirudin is at least as effective as heparin at preventing ischemic complications
• bivalirudin causes less bleeding
• bivalirudin more effective than heparin in pts with postinfarction angina
• bivalirudin works independently of antithrombin and inhibits clot bound thrombin and free thrombin
• bivalirudin: more expensive

Question 11

bivalirudin: SEs

Answer 11

• back pain
• nausea
• hypoTN
• headache
• vomiting
• abdominal pain
• pelvic pain
• anxiety
• nervousness
• insomnia
• bradycardia
• fever

Question 12

heparin: class

Answer 12

• rapid acting anticoagulant
• antithrombin activator

Question 13

heparin: MOA

Answer 13

• enhances the activity of antithrombin which is a protein that inactivates thrombin and factor Xa
  
  • so, production of fibrin is reduced, and hence clotting is suppressed

Question 14

heparin: indications

Answer 14

• prophylaxis of venous thrombosis
• used during pregnancy b/c does not cross placenta
• in situations that require rapid anticoagulation:
  
  • pulmonary embolism
  • massive CVT
• pts with open heart surgery and renal dialysis
• disseminated intravascular coagulation
• MI

Question 15

heparin: SEs

Answer 15

• chills
• fevers
• urticaria
• local irritation
• hematoma
• osteoporosis

Question 16

heparin: ADRs

Answer 16

• hemorrhage
• spinal/epidural hematoma:
  
  • pressure due to this type of bleed can cause paralysis
  • risk inc by: indwelling catheter, other anti-coagulants, antiplatelet drugs,
• heparin induced thrombocytopenia (HIT)
  
  • inc risk of DVT, PE, MI

Question 17

heparin: nursing implications

Answer 17

• contraindications:
  
  • thrombocytopenia
  • uncontrollable bleeding
  • if pt had surgery of eye, brain, spinal cord
  • lumbar puncture
  • regional anesthesia
• effects develop quickly (w/in min of IV admin)
• monitor for signs of blood loss: reduced BP, inc HR, bruises, petechiae, black stools, hematomas, pelvis pain, headache
• overdose treated with protamine sulfate
• monitor for signs of neurologic impairment
• monitor for signs of thrombosis and reduction of platelets
• administer through a heparin lock every 4-6 hours
• determine aPTT before administration and before each dose

Question 18

warfarin: class

Answer 18

• anticoagulant (oral)
• vitamin K antagonist

Question 19

warfarin: MOA

Answer 19

• suppresses coagulation by decreasing production of factors VII, IX, X, and prothrombin (all are vitamin K dependent clotting factors)
• works by inhibiting vitamin K epoxide reductase complex I (VKORCI) which is needed to convert vitamin K to its active form

Question 20

warfarin: indications

Answer 20

• long term prophylaxis of thrombosis
• prevention of venous thrombosis and PE
• prevention of thromboembolism in pts with prothetic heart valves
• prevention of thrombosis in pts with atrial fibrillation
• reduce risk of recurrent transient ischemic attacks and recurrent MI

Question 21

warfarin: SEs

Answer 21

• skin necrosis
• alopecia
• urticaria
• dermatitis
• fever
• GI distress
• red orange colored urine

Question 22

warfarin: ADRs

Answer 22

• hemorrhage
• fetal hemorrhage and teratogenesis
  
  • can cross placenta
  • can cause gross malformation, CNS defects, optic atrophy

Question 23

warfarin: contraindications

Answer 23

• contraindications:
  
  • severe thrombocytopenia
  • uncontrollable bleeding
  • pts undergoing lumbar puncture, regional anesthesia, or surgery or eye/brain/SC
  • hemophilia
  • dissecting aneurysms
  • GI ulcers
  • severe HTN
  • women anticipating abortion
  • vitamin K deficiency
  • liver dz
  • alcoholism
  • pregnancy/lactation
    
    • category X

Question 24

warfarin: nursing implications

Answer 24

• Vitamin K1 (phytonadione) is used for warfarin overdose
  
  • should be given orally or IV
• don’t administer with heparin usually b/c inc bleeding too much
• don’t take aspirin or acetaminophen with it, b/c inc effects of hemorrhage
• monitor PT and INR
• make sure pt sticks to dosing schedule
• advise pt to
  
  • avoid prolonged immobility
  • elevate legs when sitting
  • avoid tight garments on legs
  • participate in exercise
  • wear support hose
• watch for signs of bleeding: dec BP, inc HR, discolored urine/stool, bruises, petechiae
  
  • if bleeding occurs, do not administer
• avoid excess alcohol
• use soft toothbrush to prevent bleeding gums
• make sure to discontinue before major surgery (not dental)

Question 25

difference b/w warfarin and heparin

Answer 25

* heparin: * activates antithrombin, which then inactivates thrombin and factor Xa * route: IV or subQ * onset: rapid (minutes) * duration: brief (hours) * monitoring: aPTT * normal is 40 sec, but heparin should make it about 60-80 sec * antidote: protamine * warfarin: * inhibits synthesis of vitamin K dependent clotting factors including prothrombin and factor X * route: PO * onset: slow (hours) * duration: prolonged * monitoring: PT (INR) * antidote: vitamin K1

Question 26

protamine sulfate: class and indication

Answer 26

* antidote for severe heparin overdose

Question 27

protamine sulfate: MOA

Answer 27

* small protein that binds to heparin to form a complex that can't do anticoagulant activity * neutralization of heparin occurs immediately and lasts for 2 hours

Question 28

protamine sulfate: SEs

Answer 28

* dyspnea * bradycardia * flushing

Question 29

protamine sulfate: ADRs

Answer 29

* anaphylaxis * angioedema * PE

Question 30

protamine sulfate: nursing implications

Answer 30

* avoid activity that could make them bleed * IV only * give 1 mg for every 100 units of heparin * make sure pt reports recurrent bleeding

Question 31

phytonadione: class

Answer 31

* vitamin K * antidote to warfarin

Question 32

phytonadione: MOA

Answer 32

* antagonizes warfaron and can reverse warfarin induced inhibition of clotting factor synthesis

Question 33

phytonadione: indications

Answer 33

* tx of overdose of warfarin * sometimes give to liver pts

Question 34

phytonadione: SEs

Answer 34

* flushing * rash * erythema

Question 35

phytonadione: ADRs

Answer 35

* anaphylaxis (flushing, hypoTN, CV collapse) * especially if given by IV, so administer slowly

Question 36

phytonadione: nursing implications

Answer 36

* avoid activity that can cause bleeding * report any unusual bleeding