Monica - Week 4 - Exam 2

Question 1

what are the vitamin K dependent clotting factors?

Answer 1

factors 2, 7, 9, 10

Question 2

what factors does Heparin stop?

Answer 2

stops 10a and 2a (prothrombin) - powerful, able to stop 2 clotting factors - not allowing fibrin to form

Question 3

what factors does Lovenox stop?

Answer 3

stops 10a - prevents the rest of the cascade (final common pathway)

Question 4

T/F Heparin and Lovenox break down clots.

Answer 4

FALSE. they prevent clots from forming and prevent already existing clots from becoming bigger

Question 5

what is heparin (unfractionated) derived from?

Answer 5

derived from mucosal tisssues of animals (pigs and cattle) → pig intestine has natural occurring polysaccharide → anticoagulant

Question 6

what does heparin inhibit?

Answer 6

inhibits the activity of several blood coagulation factors

Question 7

how is enoxaparin obtained?

Answer 7

obtained through cleaving of heparin into smaller fragments; similar to heparin, but has shorter polysaccharide chains

Question 8

because of the shorter polysaccharide chains, this makes it a _____ _______ ________.

Answer 8

lower molecular heparin - low-molecular weight heparin (LMWH)

Question 9

when is heparin/lovenox contraindicated?

Answer 9

• if the patient has a pig/cattle allergy

- religious belief not to eat pig or cattle

Question 10

what are 3 main characteristics of antithrombin?

Answer 10

• natural anti-coagulation
• inhibits thrombin (factor 2)
• prevents conversion of fibrinogen to fibrin (keeps us from making unnecessary clots)

Question 11

antithrombin binds to ______ and _______

Answer 11

heparin and enoxaparin

Question 12

the combination of antithrombin and heparin inhibits which two factors? what does this cause?

Answer 12

inhibits factors 10a and 2a - more potent complex

Question 13

the combination of antithrombin and enoxaparin inhibits which factor? what does this cause?

Answer 13

inhibits factor 10a - less potent effect

Question 14

what are the 3 indications for the use of heparin?

Answer 14

• prophylaxis and tx of thromboembolic events
• prevents enlargement of existing clots
• prevents formation of new clots

Question 15

when is heparin commonly used?

Answer 15

post ortho and GI surgeries

Question 16

for prophylaxis, what is the normal route/dose for heparin? other characteristics?

Answer 16

• SubQ
• given q 8 - 12 hrs
• usually 5000 units
• *used in bridge therapy; 1-3 days before warfarin works
• *no monitoring needed

Question 17

although no monitoring is needed for prophylactic heparin, what labs are good to look at?

Answer 17

platelets - looking for thrombocytopenia

Question 18

for an already existing clot, what is given?

Answer 18

therapeutic heparin therapy

Question 19

for therapeutic heparin therapy, what is dosing?

Answer 19

• intermittent or continuous IV infusion

- weight based dosing

Question 20

what does the weight based dosing also take into account? who does this?

Answer 20

pharmacy is in charge of dosing; also take into account type of clot, risk factors, diagnosis, and weight

Question 21

what kind of dose is given prior to therapy? why?

Answer 21

a bolus dose is given first; helps pt achieve ↑ therapeutic level

Question 22

what labs are taken into account and have to be monitored?

Answer 22

aPTT requires monitoring

↑ therapeutic aPTT level

Question 23

what are 2 ways to best describe aPTT?

Answer 23

• used in heparin monitoring - how pharmacy knows to ↑/↓ a dose or to hold it
• measures the time (seconds) for a clot to form

Question 24

what is the control range of PTT?

Answer 24

25 - 35 seconds

Question 25

what is the therapeutic range of PTT?

Answer 25

30 - 80 seconds

Question 26

what is therapeutic range dependent on?

Answer 26

dependent on how the clot was acquired, risk factors, past medical history, what the risk of the clot is

Question 27

for intermittent infusion, when is aPTT drawn?

Answer 27

aPTT drawn 30 min before dose during initial therapy and then periodically

Question 28

for continuous infusion, when is aPTT drawn?

Answer 28

aPTT monitored q4-6hr during early therapy

- if critically high → stop heparin for 1 hr and redraw aPTT and call pharmacy

Question 29

What is HIT?

Answer 29

heparin induced thrombocytopenia

• Not common, adverse effect
• Occurs in 5% of patients on heparin

Question 30

What is heparin induced thrombocytopenia characterized by?

Answer 30

• Platelet drop by 50% from baseline

Question 31

What is the process map of thrombocytopenia?

Answer 31

• Platelet-factor-4 (PF-4) releases (no known function)
• PF4 binds to heparin and creates a complex
• Complex goes into circulation
• Platelets are activated + release PF4 (ongoing loop)
• Thrombus is formed
• Antibody response
• Thrombocytopenia (autoimmune response)

Question 32

What is enoxaparin indicated for? How does it work?

Answer 32

• Indicated for VTE phophylaxis or treatment of DVT/PE
• **hip/knee/GI surgery; possible MI in past
• Inhibits factor 10a

Question 33

What labs are monitored for prophylaxis lovenox?

Answer 33

No routine lab monitoring

Question 34

T/F: lovenox has a longer duration than heparin

Answer 34

TRUE; going given 1 - 2/day

Question 35

What should be assessed when giving lovenox?

Answer 35

thrombocytopenia and bleeding

Question 36

What teaching would go along with lovenox?

Answer 36

teaching pts how to give injections at home

Question 37

What is the normal order for lovenox for prophylaxis?

Answer 37

30-40mg daily or q12hr

Question 38

What is the normal order for coagulation treatment lovenox?

Answer 38

Weight based dose (1mg/kg q12hr or 1.5mg/kg q24hr)

Question 39

What is the anecdote for heparin?

Answer 39

Protamine sulfate IV

- Inactivates heparin and lovenox; onset 30 sec – 1 min

Question 40

What are the 7 NI for anticoagulant therapy?

Answer 40

• Never use heparin and lovenox concurrently
• Assess for signs of bleeding (nose, gums, stool, urine)
• Contraindicated w/ hemorrhagic stroke or uncontrolled HTN
• Monitor platelet count for thrombocytopenia
• Stop medication w/ signs of bleeding
• D-D interactions – warfarin, NSAIDS can ↑ bleeding
• Herbal products ↑ risk of bleeding (green tea, ginger, gingko, garlic