Therapeutics Iii Exam 5- Heparin

Front 1

therapeutic heparin lvls in blood (range)

Back 1

plasma heparin concentration of 0.3-0.7 IU/ml

Front 2

Monitoring of heparin- how to monitor (which tests)

Back 2

Activated partial thromboplastin time (aPTT)

Front 3

Therapeutic aPTT range

Back 3

wahtever range correlates to heparin conc. of 0.3-0.7 (varies from lab to lab)

Front 4

recs for monitoring- when to check aPTT

implications

Back 4

Check aPTT at baseline and at 6 hours after initiation or dose adjustment until stable- so can take a while to reach therapeutic level depending on # of doses

Front 5

contraindications of heparin (7) which is the biggest?

Back 5

Hypersensitivity to heparin
History of HIT
Thrombocytopenia/Active bleeding/Hemophilia (just...incr. bleeding risk)
Liver disease with elevated baseline PT
Inability to monitor therapy***

Front 6

Adverse Effects of heparin (3)

Back 6

Hemorrhage
Osteoporosis
Thrombocytopenia

Front 7

risk factors for hemorrhage (4)

Back 7

recent surgery or trauma
use of other agents which increase bleeding risk
renal failure (? CL of hep?)
older age

Front 8

monitoring for hemorrhage on heparin- what to look for? (2)

when to monitor? (2)

Back 8

Monitor hemoglobin and hematocrit regularly (baseline and 2-3 times per week)

drop in 2 on Hgb

Front 9

what is used to reverse heparin bleeds

Back 9

protamine

Front 10

dosing of protamine- how much will neutralize how much heparin

how to calc protamine dose

Back 10

1mg IV protamine will neutralize 100 units of UFH (max dose = 50mg)

Consider heparin dose over previous 2-2.5 hours only

Front 11

protamine ADR (3)

Back 11

hypotension, bradycardia, allergic reaction

Front 12

heparin induced osteoporosis mechanism

only and issue when?

Back 12

Heparin binds to osteoblasts resulting in activation of osteoclasts
Long-term, high-dose therapy

Front 13

2 types of heparin thrombocytopenia (which is more common)

Back 13

Heparin Associated Thrombocytopenia (HAT)** more common- not a big deal

Heparin Induced Thrombocytopenia (HIT)

Front 14

HAT- properties (2)

Back 14

Mild, transient fall in platelets between day 2-4 of therapy
Platelets generally recover without discontinuation of heparin

Front 15

Heparin Induced Thrombocytopenia (HIT)- properties (3) dangers, mechanism, etc

Back 15

Antibody mediated
High risk of thrombotic complications
Life-threatening

Front 16

Heparin Induced Thrombocytopenia- when do platelets start falling (2)

Back 16

Initial platelet count fall: 5-10 days after initiation (if not in that time frame, probably not HIT)

also have Rapid-onset HIT- within first 24 hrs

Front 17

how to monitor for HIT/duration/frequency

Back 17

Platelet monitoring Every 2-3 days from day 4-14 (or until heparin stopped)

Front 18

diagnostic definition of HIT (labs)

Back 18

≥50% fall in platelet count and/or thrombotic event 4-14 days after starting heparin

Front 19

the 4Ts- assessing HIT

Back 19

thrombocytopenia with nadir > 20
timing of platelet count fall
thrombosis (new)
other causes of thrombocytopenia? (if none = high risk for HIT)

Front 20

Laboratory Assessment for HIT (2)

Back 20

ELISA- for PF (platelet factor) 4-heparin antibodies can rule it out

Serotonin Release Assay (SRA)- gold standard- but not used

Front 21

Goal of HIT management

Back 21

prevent thrombosis

Front 22

2 steps in treating HIT

Back 22

ALL sources of heparin (including flushes) must be discontinued
Initiate alternative anticoagulant therapy

Front 23

most common treatment for HIT (2)

Back 23

Lepirudin
Argatroban

(direct thrombin inhibitors)

Front 24

what NOT to use in HIT (3)

Back 24

LMWH, warfarin, and aspirin should NOT be used for acute management of HIT

if given warfarin actually want to reverse it with vitamin K - then after HIT you can start it again

Front 25

Lepirudin dosing- bolus? initial dosing

Back 25

avoid bolus because of high bleed risk

Initial IV infusion rate not higher than 0.1 mg/kg/hr

Front 26

lepirudin monitoring- what lab?
therapeutic range of this lab test?

how often to monitor

Back 26

maintain APTT 1.5-2 times baseline
aPTT recommended at 4 hour intervals

Front 27

renal dosing of lepirudin- (2)

Back 27

Renally eliminated so
Avoid bolus and lower infusion rate

Front 28

Argatroban- effect on INR

Back 28

increases it more than other direct thrombin inhibitors- can complicate conversion back to warfarin

Front 29

argatroban- elimination

Back 29

hepatobiliary

Front 30

3 LMWH types

Back 30

Enoxaparin
Dalteparin
Tinzaparin

Front 31

advantages of LMWH over UFH (5)

Back 31

More predictable dose response
Increased SQ bioavailability
Longer half-life
Lower incidence of thrombocytopenia
Less need for laboratory monitoring

Front 32

MoA of LMWH (3)

Back 32

Binds to and enhances activity of antithrombin
Less effect on factor II (thrombin)
Greater effect on factor Xa

Front 33

LMWH: BA, peak effect, clearance

Back 33

90% bioavailable
Peak effect in 3-5 hours
Cleared renally (prolonged in renal impairment)

Front 34

dosing LMWH in fatties

what if they are sooo fat they exceed the max syringe size

Back 34

dose based on total body weight

pt > 150 kg- who knows, cap at 150 BID in these cases and consider monitoring anti-Xa levels 4 hours after dose (peak level)- but nothing really there to guide you...based on anti Xa lvls...

Front 35

Low Molecular Weight Heparin dosing: route

Back 35

Given via SQ injection in abdomen

Front 36

Enoxaparin dosing
only dose approved for outpatient use

renal dosing

Back 36

1mg/kg q12 hours** (for outpt) or 1.5mg/kg q24 hours
increase frequency x2 (so q24 hrs for 1 mg/kg)

Front 37

avail. of enoxaparin syringes (7)

Back 37

30mg, 40mg, 60mg, 80mg, 100mg, 120mg, 150mg

round to nearest syringe size

Front 38

renal dosing for enoxaparin- if impaired, what are your risks (2)

Back 38

Clearance of anti-Xa effect strongly correlated with CrCl
Increased risk for bleeding

Front 39

what do you recommend in terms of enoxaparin dosing if CrCl < 30 ml/min

Back 39

Generally recommend UFH for severe renal impairment (CrCl<30mL/min) + Anti-Xa level monitoring

Front 40

LMWH in pregnancy properties (2) and pregnancy category

Back 40

LMWHs do not cross the placenta
Appear relatively safe and are an alternative to UFH for long-term use
Pregnancy category B

Front 41

LMWH AE (3)

Back 41

Hemorrhage
Thrombocytopenia (lower than in UFH)
Osteoporosis- also less than with UFH

Front 42

protamine neutralization of LMWH vs. UFH

Back 42

Protamine neutralizes ~60% anti-Xa activity of LMWH

Front 43

boxed warning on LMWH

Back 43

risk of spinal/epidural hematoma in patients undergoing spinal or epidural anesthesia or spinal puncture- bridging therapy use of LMWH- if they are getting epidural, make sure LMWH is not given within 24 hrs of op

Front 44

protamine dosing for LMWH bleeds

typical dose- (and max)

additional dose

Back 44

1 mg protamine per 100 anti-Xa units LMWH up to max of 50 mg (1mg enoxaparin = ~100 anti-Xa units)
A second dose of 0.5 mg protamine per 100 anti-Xa units may be given if continued bleeding

Front 45

LMWH monitoring (3)

Back 45

Routine monitoring for efficacy not necessary
Baseline CBC with platelets, repeat every 5-10 days
Anti-factor Xa monitoring not routinely recommended for most patients, only special pops (fatties, pregnant)

Front 46

contraindications to LMWH (3)

Back 46

Hypersensitivity
History of HIT
Active bleeding

Front 47

hypersensitivity issues in LMWH- what allergen sensitivity should you look for (4)

Back 47

LMWH, UFH, pork products, sulfites

Front 48

fondaparinux MoA (what is it, MoA)
no effect on what

Back 48

Pentasaccharide Factor Xa Inhibitor
binds to antithrombin and specifically inhibits factor Xa

no effect on thrombin directly

Front 49

dosing of fondaparinux:
50-100 kg (most patients)

fatties (>100 kg)
skinnies (<50 kg)

know the frequency of dosing

Back 49

If <50 kg, dose is 5 mg SQ q24 hours
50-100 kg, dose is 7.5 mg SQ q24 hours
If >100 kg, dose is 10 mg SQ q24 hours

Front 50

renal dosing of fondaparinux (note the CrCl range that this is used in)

Back 50

Reduce dose by 50% if CrCl 30-50mL/min

Front 51

fondaparinux contraindiction

Back 51

Contraindicated in severe renal impairment (CrCl <30)

Front 52

efficacy monitoring of fondaparinux?

Back 52

No routine coagulation testing required

Front 53

fondaparinux AE

Back 53

hemorrhage- no antidote

Front 54

possible antidote for fondaparinux bleeding

Back 54

Recombinant factor VIIa may be effective for uncontrolled bleeding

Front 55

Fondaparinux and HIT (2)

Back 55

Generally not believed to cause HIT
Sometimes used in treatment of HIT, not an FDA approved indication

Front 56

fondaparinux and pregnancy (3)

Back 56

Pregnancy category: B
but not used often as not as much evidence
Excretion into breast milk in humans unknown

Front 57

oral version of fondaparinux

Back 57

Rivaroxaban

Front 58

Direct Thrombin Inhibitors (2)

Back 58

argatroban
-rudins

Front 59

oral direct thrombin inhibitor

Back 59

Dabigatran

Front 60

Thrombolytic Therapy indication (2)

Back 60

PE with hemodynamic compromise
Massive DVT with limb gangrene

Front 61

Thrombolytic Therapy downside

Back 61

SEVERE risk of hemorrhage

Front 62

Thrombolytic agents (3)

Back 62

Alteplase
Streptokinase
Urokinase

Front 63

Thrombolytic Therapy routes (2) which is preferred

Back 63

Catheter-directed (preferred- local) systemic

Front 64

Venous thrombectomy- reserved only for whom? (1 general, 3 specific)

Back 64

only for very high risk pt where thrombolytic therapy is contraindicated

Significant iliofemoral venous thrombosis
PE associated with pulmonary HTN, hypoxemia, and right heart failure
Not a candidate for or no response to thrombolysis

Front 65

venous thrombectomy- what is it?

do you still need anticoagulation?

Back 65

Extract thrombus using balloon catheter
Anticoagulation still required during and after the procedure