Anti-Coagulation In Lecture Flashcards
Virchow’s Triad
- abnormalities of clotting components (hypercoagulable state)
- abnormality of surfaces in contact with blood flow (endothelial injury)
- abnormalities in blood flow (circulatory stasis)
DOACs for post operative prophylaxis
- dabigatran
- rivaroxaban
- apixaban
Dabigatran dosing changes (post-op prop doses)
- day of surgery = 110 mg QD
- not day of surgery = 220 mg QD
- maintenance dose = 220 mg QD
Dabigatran is for ____ only
HIP ONLY
Rivaroxaban dosing (post-op prop doses)
10 mg QD x35 days
Apixaban dosing (post-op prop doses)
2.5 mg BID x 35 days
Rivaroxaban (post-op prop doses) avoid use when
CrCl is < 30 ml/min
DOACs for non-valvular atrial fibrillation
- dabigatran
- rivaroxaban
- apixaban
- edoxaban
Dabigatran (non-valvular atrial fibrillation dosing)
150 mg BID
Rivaroxaban (non-valvular atrial fibrillation dosing)
20 mg QD
Apixaban (non-valvular atrial fibrillation dosing)
5 mg BID
Edoxaban (non-valvular atrial fibrillation dosing)
60 mg PO QD
Remember that all DOACs are
adjusted for renal flow
How to renally adjust DOACs for non-valvular atrial fibrillation dosing
- dabigatran, rivaroxaban, edoxaban are adjusted based on CrCl
- Apixaban dosing based on SCr
Edoxaban should not be used for non valvular atrial fibrillation when
CrCl is > 95 ml/min
Apixaban dosing for non-valvular atrial fibrillation is based on (3 things)
- age (>/= 80)
- SCr (< 1.5 mg/dl)
- Weight (= 60 kg)
DOACs for DVT/PE treatment
- dabigatran
- rivaroxaban
- apixaban
- edoxaban
Dabigatran DVT/PE treatment dosing
150 mg BID
Rivaroxaban DVT/PE treatment dosing
15 mg BID x 3 weeks, then 20 mg QD
Apixaban DVT/PE treatment dosing
10 mg BID x7 days, followed by 5 mg BID
Edoxaban DVT/PE treatment dosing
60 mg QD
Apixaban renal adjustment dosing based on
SCr (> 2.5 mg/dL)
DOACs for DVT/PE tx: dabigatran and edoxaban…
require 5 - 10 days parental anticoagulation
Edoxaban (DVT/PE treatment) is wt is
= 60 kg = dose is 30 mg QD
For DVT/PE tx, which DOACs don’t require parental anticoagulation
rivaroxaban and apixaban
DOACs for secondary treatment of recurrent DVT/PE
rivaroxaban and apixaban
Rivaroxaban dosing for secondary treatment of recurrent DVT/PE
20 mg PO QD
Apixaban dosing for secondary treatment of recurrent DVT/PE
2.5 mg PO BID
For both rivaroxaban and apixaban for secondary treatment of recurrent DVT/PE…
this is considered after an initial 6 months of treatment (these drugs can be used during months 6 - 12)
DOACs that can be used for VTE prophylaxis (for acutely ill patients)
rivaroxaban and BETRIXABAN (ONLY PLACE THIS SHOWS UP)
Rivaroxaban VTE prophylaxis dosing
10 mg PO QD (31 - 39 days)
Betrixaban VTE prophylaxis dosing
160 mg PO QD (Day 1); 80 mg PO QD (35 - 42 days)
Warfarin Initial Dose (same dose if unsure)
5 mg PO QD
Warfarin Initial Dose for Healthy Outpatients
10 mg PO QD
Warfarin should be overlapped with
UFH or LMWH for at least 5 days and until INR is therapeutic
Must adjust the ______ dose to achieve therapeutic INR
weekly dose
The one exception when a pt may be started on just warfarin
when the pt has atrial fibrillation
Goal INR of 2.0 - 3.0 recommended for pts with
- prophylaxis of VTE
- tx of VTE or PE
- Prevention of systemic embolism (tissue heart valves, AMI, valvular heart disease, atrial fibrillation)
- antiphospholipid antibody syndrome
- mechanical heart value (aortic)
INR goal of 1.5 - 2.0 when
the pt has an aortic valve replacement - mechanical On-X
INR goal of 2.5 - 3.5 when
the pt has a mechanical heart valve (mitral, caged ball, high risk)
AMI is an oral anticoagulant that prevents
recurrent MI, INR of 2.5 - 3.5 is recommended
Warfarin Maintenance therapy: If dose held today
check within 1 - 2 days
Warfarin Maintenance therapy: If dose change today
check within 1 - 2 weeks
Warfarin Maintenance therapy: If dosage change = 2 weeks ago
check within 2 - 4 weeks
Warfarin Maintenance therapy: Routine follow-up for stable pt
check every 4 - 6 weeks
Warfarin Maintenance therapy: Routine follow-up for unstable pt
check every 1 - 2 weeks
Warfarin Maintenance therapy: Consistently stable (i.e. no change in 6 months
check every 12 weeks
Patient Interview: Warfarin Questions
- 5 Ds:
- Drugs (interactions)
- Diseases (changes in overall medical condition)
- Doses (any missed doses)
- Diet (any changes, specifically leafy green vegetables)
- Drink (any alcohol consumption)
*Bruising/bleeding
When to have a warfarin dose adjustment
- s/sx of bleeding
- thromboembolic complications
- prescription medication changes
- diet
- activity
- etoh use
- AE
- OTC drug use
- drug interaction screening
Warfarin Protocol: Goal = 2.0 - 3.0
- INR < 2 = Increase 5 - 15%
- INR 3.1 - 3.5 = Decrease by 5 - 15%
- INR 3.5 - 4.0 = Hold 0 - 1 dose, decrease by 10 - 15%
- INR > 4.0 = Hold 0 - 2 doses, decrease by 10 - 15%
Warfarin Protocol: Goal = 2.5 - 3.5
- INR < 2.5 = Increase 5 - 15%
- INR 3.6 - 4.0 = Decrease by 5 - 15%
- INR 4.1 - 4.5 = Hold 0 - 1 dose, decrease by 10 - 15%
- INR > 4.5 = Hold 0 - 2 doses, decrease by 10 - 15%
Bridging warfarin not required for
new anticoagulants and typically not for dental, dermatologic, or cataract procedures
In warfarin bridging is needed (i.e. during an invasive procedure)
-stop warfarin 5 days before surgery
- give LMWH or UFH until the procedure
- **stop LMWH 24 hrs before procedure
- **stop IV UFH 4 - 6 hrs before procedure
-resume warfarin 12 - 24 hours after surgery (assuming adequate hemostasis)
The LMWH usually used to bridge warfarin is
enoxaparin
