Module 2 exam 1 Dosage adjustment Flashcards
What to do when INR<2 (or 2.5 if goal is 2.5-3.5)
Increase weekly dose by 5-15%
What to do when INR is 3.1-3.5 (3.6-4 if goal is 2.5-3.5)
decrease weekly dose by 5-15%
What to do when INR is 3.5-4 (4.1-4.5 if goal is 2.5-3.5)
hold 0-1 dose
decrease by 10-15%
What to do when INR>4 (>4.5 if goal is 2.5-3.5)
hold 0-2 doses
decrease by 10-15%
What to do when some doses are different than the doses taken most days
Space out the separate doses by as much as possibe
ie- if 2 doses different- M,F
If 3 doses different M,W,F
Switch/flip
Never choose only 1 day a week different dose
What is a switch/flip
3 days at lower dose and 4 days at higher dose, we switch to 3 days at higher dose and 4 days at lower dose
What is bridging therapy? when is it used?
Bridging therapy is when a patient needs to come off warfarin around a procedure that has bleeding risk
When to stop warfarin if bridging is needed
5 days before surgery
When to stop aspirin if bridging is needed
a week before procedure
What to do once we stop warfarin and aspirin during bridging
Start enoxaparin a day after stopping warfarin (there will be a day with no medication at all)
What to do with different doses of enoxaparin when we approach surgery day
If enoxaparin is 12 hr dosing, no enoxaparin the night before and the day of procedure
If enoxaparin is 24 hr dosing, The last dose should be 50% of the dose the morning before the surgery
How do we start warfarin back up after surgery on enoxaparin
overlap warfarin and enoxaparin for atleast 5 days AND INR>2
What is the max INR should increase or decrease ina day
0.3 increase or decrease.
How do we monitor patients on UFH
aPTT
Goal aPTT
1.5-2.5
low aPTT we need to increase dose
What are the two types of thrombocytopenia
HAT (type 1)
HIT (type 2)
Difference between HAT and HIT
HAT- platelets>100,000
HIT- platelets <100,000
or platelet decrease by more than 50%
Occurs in 7-14 days
Tx of HIT
Stop all heparin products
give alternate anticoagulant (lepirudin, argatroban, bivalirudin, fondaparinux)
Do not give warfarin until platelet >150,000
Can we continue all heparin products in HAT
Yes, only stop in HIT)
Compare advantage of LMWH and UFH
LMWH has better bioavailability and more predictable dosing
longer plasma life
improved subq
lower risk of HIT
What are the different doses of enoxaparin
Prophylaxis after surgery- 30 mg SQ, Q 12 H
Prophylaxis for hospital- 40 mg QD subq
Tx dose- 1 mg/kg Q12H
or
1.5 mg/kg/day
Enoxaparin doses for Crcl<30
prophylaxis- 30 mg SQ daily
tx- 1mg/kg
What kind of drug is enoxaparin
LMWH
Which patients to monitor for LMWH (enoxaparin)
Monitor anti Xa levels of
Children, severe kidney failure, obesity, pregnancy
Different ways of monitoring anti Xa in LMWH pts
If pt is on twice a day enoxaparin- monitor PEAK anti Xa level 4 hours after a dose is give. (concentration goal 0.6-1)
If patient is on once a day dosing- Check TROUGH concentration immediately before a dose is given to see if it has been cleared.
(concentration goal 0.1-0.3)
Name an injectable Fxa inhibitor
Fondaparinux
What is fondaparinux used for? doses?
Used for tx of DVT or PE
prophylaxis -2.5 mg
tx doses <50 kg- 5 mg QD
50-100 kg- 7.5 mg
>100 kg- 10 mg
In what situations can we not use Fondaparinux
Do not use CrCL<30
Do not use prophylaxis<50 kg
Can be used if pt has HIT diagnosis
Name DTI drugs. WHat are they used for
Lepirudin, Bivalirudin, Argatroban
All reserved for use when pt is diagnosed with HIT
Argatroban important point
One of the few drugs dosed hepatically, adjust dose based on renal impairment.
ARGATROBAN CAN FALSLY ELEVATE INR
When to discontinue medications when using with warfarin
stop other meds when INR is 2, except argatroban,
Stop argatroban when INR is 4
When using warfarin and using enoxaparin to replace or supplement warfarin, we use therapeutic dose
Dont forget
