Allison Burnett, PharmD, CACP, PhC Clinical Assistant ... · Allison Burnett, PharmD, CACP, PhC Clinical Assistant Professor- UNM College of Rx Antithrombosis Stewardship Pharmacist

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Special and High-Risk Situations

Allison Burnett, PharmD, CACP, PhC Clinical Assistant Professor- UNM College of Rx

Antithrombosis Stewardship Pharmacist University of New Mexico Hospital

[email protected] 505.306.8987

National Conference for Nurse Practitioners (NCNP) May 12, 2016

Orlando, Florida

Explain peri-operative anticoagulant strategies and the current body of evidence for this practice

Discuss risks associated with concomitant anticoagulant and antiplatelet therapies and possible management strategies to mitigate these risks

Describe approaches for urgent or emergent reversal of anticoagulation

• Anticoagulation Forum (non-profit)

• Board member

• Honoraria

• Society of Hospital Medicine (non-profit)

• Honoraria

mailto:[email protected]

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A 62-year-old male with atrial fibrillation (CHADS2-VASc score of 2 for DM, HTN) on warfarin for stroke prevention is scheduled to undergo total knee replacement in a few weeks. Labs: SCr 0.7 mg/dL, weight 83 kg, Hgb 10.2, Hct 31 Which of the following describes the best course of action for his peri-procedural anticoagulation?

A. Do not interrupt warfarin therapy for this procedure, as it is low bleed risk

B. Hold warfarin for 5 days prior to the procedure and bridge with full dose LMWH pre- and post-operatively

C. Hold warfarin for 5 days prior to the procedure and do not use pre-op bridging, but employ post-op DVT prophylaxis (along with resuming

warfarin) until INR >2 D. Just hold warfarin for 2-3 days prior to the procedure

Approximately 2 – 3 million people in the U.S. take anticoagulants ~250,000 patients annually in the US evaluated for anticoagulation

management around elective procedures The peri-procedural period may pose a particularly high-risk time

for both thrombosis and bleeding First question: Does anticoagulation even need to be interrupted? ◦ Based on bleed risk of procedure ◦ Also consider inherit patient characteristics that may contribute

to bleeding (previous major bleeds, renal impairment, concomitant antiplatelet use)

Spyropolous AC, et al. Blood 2012; 120(15): 2954-62. Douketis JD. Chest. 2012 Feb;141(2 Suppl):e326S-50S. PMID: 22315266.

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Most inpatient surgical procedures are considered high bleeding risk

◦ Goal is to have little to no anticoagulant effect during surgery

◦ Take particular care in very high-risk procedures: e.g., neurosurgery, neuraxial procedures, vascular surgery

Low bleed risk procedures

◦ Acceptable to have some residual anticoagulation during the procedure

◦ Hold anticoagulation for shorter period of time

Douketis JD. Chest. 2012 Feb;141(2 Suppl):e326S-50S. PMID: 22315266.

Minor dental procedures (e.g., tooth extraction) ◦ continue VKAs with co-administration of an oral prohemostatic agent -

or - ◦ stop VKAs 2 to 3 days before the procedure instead of alternative

strategies (Grade 2C)

Minor dermatologic procedures ◦ Continue VKAs around the time of the procedure and

optimize local hemostasis instead of other strategies (Grade 2C)

Cataract surgery ◦ Continue VKAs around the time of the surgery instead of

other strategies (Grade 2C)

Douketis JD. Chest. 2012 Feb;141(2 Suppl):e326S-50S. PMID: 22315266.

Baron TH, et al. N Engl J Med 2013; 368: 2113-24. Douketis JD. Chest. 2012 Feb;141(2 Suppl):e326S-50S. PMID: 22315266

Our patient

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Warfarin has extremely long t1/2 (~ 40 hours) Requires ~ 5 days to achieve nadir of

anticoagulant effect

If temporary interruption is indicated, warfarin patients should begin holding warfarin 5 days prior to procedure to allow normalization of the INR

May consider shorter hold time of 2-3

days for low bleed risk procedures

Next question: Should peri-operative “bridging” be employed in my patient?

Based on risk for thromboembolic event while off anticoagulation

Arterial and venous clots have different consequences

◦ AF-related stroke 25% 30-day mortality

◦ VTE case fatality rate approximately 11%

Spyropolous AC, et al. Blood 2012; 120(15): 2954-62

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INR

Surgery day

Vulnerable period

Target INR for most major surgical procedures is ≤1.5

(equivalent to plasma conc. of 40% functioning clotting factors)

Siegal D. Circulation. 2012 Sep 25;126(13):1630-9. PMID: 22912386

Study Thromboembolism Bleeding Douketis, J, Healey, J, et al.

Subanalysis of the RE-LY trial.

Thromb Haemost. 2015 Mar; 113(3): 625-32.

n=4591

Dabigatran:

Bridged 0.5%

Not bridged 0.3%

(p= 0.46)

Warfarin patients:

Bridged 0.5%

Not bridged 0.2%

(p= 0.321)

Dabigatran:

Bridged 6.5%

Not bridged 1.8%

(p<0.001) Warfarin patients: Bridged 6.8% Not bridged 1.6% (p<0.001)

Clark, N. et al. Retrospective review of bridging

in VTE patients

JAMA 2015 July. 175(7):1163-1168.

n= 1178

No significant difference

between bridged and non-

bridged groups

(p=0.56)

Bridge therapy: 2.7%

Non-bridged therapy: 0.2% (HR 17.2; 95% CI 3.9-75.1)

Matthew, J, et al.

Early bridging after mechanical valve

placement

Thromb Haemost. 2014. doi 1000472053.

n=1777

No significant difference

between treatment and

prophylactic dosing bridging

(1.8% vs. 2.1%; OR 0.9; 95% CI

0.37-2.18;p=0.81)

Therapeutic dosing: 5.4%

Prophylactic dosing: 1.9% (OR 3.23; 95% 1.58-6.62; p=0.001)

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• Randomized, double-blind, placebo controlled trial of therapeutic bridge therapy in patients interrupting warfarin with AF (n=1884) ◦ Dalteparin 100 IU/kg twice daily

◦ Placebo injections twice daily

• 30 day outcomes of stroke, systemic embolism, transient ischemic attack, and major bleeding

N Engl J Med 2015; 373:823-833: doi 10.1056/NEJMoa1501035

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Warfarin should be resumed the night of the procedure if: ◦ Hemostasis achieved

◦ No further invasive procedures anticipated

If parenteral bridging is indicated

◦ High bleed risk procedure

Initiate post-op DVT prophylaxis with LMWH at ~ 24 hours post-op

If tolerated, increase to therapeutic LWMH at 48-72 hours

◦ Low bleed risk procedure

Initiate therapeutic LMWH at ~ 24 hours post-op

◦ Discontinue bridge once INR is >2

Take home message(s): Most non-valvular atrial fibrillation (NVAF) patients

should not be bridged ◦ Controversy still exists for NVAF patients with CHA2DS2-VASC

scores of ≥ 4…

Collective evidence is calling in to question the utility of bridging in other anticoagulation populations as well

Use of no bridging or prophylactic dose regimens may be

reasonable and safer in many patients

A 62-year-old male with atrial fibrillation (CHADS2-VASc score of 2 for DM, HTN) on warfarin for stroke prevention is scheduled to undergo total knee replacement in a few weeks. Labs: SCr 0.7 mg/dL, weight 83 kg, Hgb 10.2, Hct 31 Which of the following describes the best course of action for his peri-procedural anticoagulation?

A. Do not interrupt warfarin therapy for this procedure, as it is low bleed risk

B. Hold warfarin for 5 days prior to the procedure and bridge with full dose LMWH pre- and post-operatively

C. Hold warfarin for 5 days prior to the procedure and do not use pre-op bridging, but employ post-op DVT prophylaxis (along with resuming

warfarin) until INR >2 D. Just hold warfarin for 2-3 days prior to the procedure

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A 62-year-old male with atrial fibrillation (CHADS2 score of 2 for DM, HTN) on a DOAC for stroke prevention is scheduled to undergo total knee replacement in a few weeks. Labs: SCr 0.7 mg/dL, weight 83 kg, Hgb 10.2, Hct 31 Which of the following describes the best course of action for his peri-procedural anticoagulation?

A. Do not interrupt DOAC therapy for this procedure B. Hold DOAC for 2-3 half-lives prior to this low bleed risk

procedure C. Hold DOAC for 4-5 half-lives prior to this high bleed risk

procedure D. Hold DOAC for 5 days prior to procedure and use LMWH as

bridging therapy

Rapid onset/offset of DOACs precludes need for peri-operative bridging with heparin or LMWH

DOACs and LMWH are pharmacokinetically similar ◦ Overlapping these agents will lead to overanticoagulation

DO NOT BRIDGE DOAC PATIENTS Timing of cessation and resumption of DOAC is based on: ◦ Patient’s current renal function ◦ Half-life of DOAC ◦ Bleeding risk associated with procedure

Cessation of DOAC ◦ Dependent half-life of specific DOAC in correlation with

patient’s current renal function Half-lives ranges from 6-17 hours, depending on DOAC Will be prolonged with renal impairment

May require longer pre-op hold time

◦ Dependent on type of procedure Low bleed risk: hold for 2-3 half-lives

High bleed risk: hold for 4-5 half lives

Stangier J, et al. Clin Pharmacokinet 2010; 49(4): 259-68.

Spyropolous AC, et al. Blood 2012; 120(15): 2954-62.

Elective Procedures

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Table available in: “Practical Management of

DOACs in VTE”

Journal of Thrombosis & Thrombolysis

Jan 2016 (open access)

Resumption of DOAC ◦ DOACs have rapid onset of anticoagulant effect (~1-4 hours) Analogous to using LMWH Caution with resuming too soon or too aggressively

◦ Timing of resumption dependent on type of procedure Low bleed risk: resume 12-24 hours post-op High bleed risk: resume 48-72 hours post-op

◦ May consider “step-up” approach Lower or prophylactic dose of DOAC for initial 24-48 hours If tolerated, increase to treatment dose DOAC at 48-72 hours


A 62-year-old male with atrial fibrillation (CHADS2 score of 2 for DM, HTN) on a DOAC for stroke prevention is scheduled to undergo total knee replacement in a few weeks. Labs: SCr 0.7 mg/dL, weight 83 kg, Hgb 10.2, Hct 31 Which of the following describes the best course of action for his peri-procedural anticoagulation?

A. Do not interrupt DOAC therapy for this procedure B. Hold DOAC for 2-3 half-lives prior to this low bleed risk

procedure C. Hold DOAC for 4-5 half-lives prior to this high bleed risk

procedure D. Hold DOAC for 5 days prior to procedure and use LMWH as

bridging therapy

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Concomitant antiplatelets – If non-cardiac indication, likely okay to interrupt – If cardiac indication, consult with cardiology

Delayed resumption of oral medications – Patient unable to take PO post-procedure – Concern for impaired gastrointestinal absorption (e.g., post-op ileus) – Consider use of parenteral anticoagulant until patient can be

appropriately transitioned back to warfarin or DOAC

Epidural or spinal anesthesia – Close communication and collaboration with anesthesia team – Follow guidelines from the American Society of Regional Anesthesia


https://www.asra.com/advisory-guidelines/article/1/anticoagulation-3rd-edition




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A 71-year-old female on dabigatran 150 mg BID for NVAF (CHA2DS2VASc = 5) was admitted for ACS and emergently taken to the cath lab for percutaneous coronary intervention (PCI). She was found to have multi-vessel disease and had 2 drug-eluting stents placed, which will require dual antiplatelet therapy (DAPT). Her HAS-BLED score is 4.

Which of the following antithrombotic strategies would be recommended for her?

A. Continue dual antiplatelet therapy alone

B. Switch patient to warfarin along with aspirin 325 mg and clopidogrel and continue indefinitely

C. Continue dabigatran at a lower dose along with aspirin 81 mg and clopidogrel for at least a month

D. Continue dabigatran along with aspirin 81 mg and ticagrelor for at least a month

HAS-BLED ≥ 3 = high risk for bleed CHA2DS2VASc preferred (2014 AHA/ACC/HRS

Guidelines for Management of Patients with AF)

CHA2DS2-VASc

Risk

Antithrombotic Recommendation

0 Low ASA (or none)

1 Intermediate Anticoagulation

(preferred) or ASA

≥2 High Anticoagulation

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Concomitant Need for Antiplatelets and

Anticoagulants

The “Triple Therapy” Dilemma

Antiplatelets Anticoagulants

Clopidogrel + Aspirin

Prasugrel + Aspirin

Ticagrelor + Aspirin

Apixaban

Dabigatran

Edoxaban

Rivaroxaban

Warfarin

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Therapy Regimen HR (95% CI)

Warfarin monotherapy 1 (Reference)

Aspirin monotherapy 0.93 (0.88–0.98)

Clopidogrel monotherapy 1.06 (0.87–1.29)

Aspirin + clopidogrel 1.66 (1.32–2.04)

Warfarin + aspirin 1.83 (1.72–1.96)

Warfarin + clopidogrel 3.08 (2.32–3.91)

Triple therapy 3.70 (2.89–4.76)

Risk of Bleeding with Single, Dual, or Triple Antithrombotic Therapy

Adapted from: Hansen ML. Arch Intern Med 2010;170:1433-41.

Patients on chronic anticoagulation undergoing PCI followed 1 year

Triple therapy

ASA (81 mg), clopidogrel, warfarin

Clopidogrel + warfarin

Dewilde W. Lancet 2013;381:1107-15.

TAT vs. Warfarin + Clopidogrel in ACS +AF: The WOEST Trial

Treatment Primary End Point Any Bleeding (%)

HR (95% CI) Stent Thrombosis

Triple therapy 44.4 0.36 (0.26–0.50) p<0.0001

No difference

Clopidogrel + warfarin

19.4

R

Warfarin and Antiplatelets in Atrial Fibrillation After MI or ACS

Antithrombotic Treatment Regimens:

• Warfarin, clopidogrel or aspirin alone

• Dual antiplatelet therapy

• Warfarin plus aspirin

• Warfarin plus clopidogrel

• Warfarin plus clopidogrel and aspirin Results:

• Warfarin plus clopidogrel = TAT in safety and efficacy

• All-cause mortality was significantly higher in all other study arms

Lambert et al. J Am Coll Cardiol. 2013 Sep 10;62(11):981-9.

N = 12,165

Lambert et al. J Am Coll Cardiol. 2013 Sep 10;62(11):981-9.

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Risk-Stratified Recommendations: Stroke Prophylaxis in AF

Assess Thromboembolic Risk CHA2DS2-VASc

CHA2DS2-VASc = 0

CHA2DS2-VASc = 1

CHA2DS2-VASc ≥ 2, hx stroke/TIA

OAC

January CT. J Am Coll Cardiol. 2014;64(21):2246-2280. doi:10.1016/j.jacc.2014.03.021

Warfarin: Level A DOAC: Level B

No therapy reasonable: IIa, Level B

No therapy or ASA or OAC: IIb, Level C

OAC + clopidogrel

Data from DOAC ACS trials

DAPT + dabigatran: Dose-dependent increase in major or clinically relevant non-major bleeding without significant reduction in cardiovascular ischemic events

• Post hoc RE-LY: SAPT + dabigatran increased bleeding 60%; DAPT + dabigatran increased bleeding 130%

DAPT + apixaban: increased major and fatal bleeding without a reduction in ischemic events

DAPT + rivaroxaban: reduced ischemic events but increased major bleeding

What About DOAC + Dual Antiplatelets?

Dans AL. Circulation 2013;127:634-40; Alexander JH. NEJM 2011;365:699-708; Mega JL. NEJM 2012;366:9-19.

Major bleeding doubled in all triple therapy groups.

Oral anticoagulant Trial Name (NCT#)

Dabigatran REDUAL-PCI (NCT02164864)

Rivaroxaban PIONEER (NCT01830543)

Apixaban AUGUSTUS (NCT02415400)

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Strategies to Reduce Bleed Risk

Possible Strategies

Target INR 2-2.5*

Proton Pump Inhibitor

Bare Metal Stent (BMS) Versus Drug Eluting (DES)

Dual Antiplatelet Therapy*

Warfarin PLUS Single

Antiplatelet Therapy

BMS Antiplatelet Therapy: > 1 month DES Antiplatelet Therapy: > 3 to 6 months

*Does not apply to patients with valves Amsterdam et al. J Am Coll Cardiol. 2014;64(24):2645-2687. O’Gara et al. J Am Coll Cardiol. 2013;61(4):e78-e140 Rossini et al. Am J Cardiol. 2008 Dec 15;102(12):1618-23.

Use CHA2DS2-VASc and HAS-BLED assessment

• If HAS-BLED ≥3, consider avoid triple antithrombotic therapy (TAT)

May consider DAPT without anticoagulation

May consider OAC+ single antiplatelet therapy (SAPT)

• Clopidogrel + warfarin most evidence-based option currently

• After minimum duration of SAPT + warfarin, consider monotherapy with warfarin or DOAC

Until more data become available, best to avoid DOACs and 2nd generation P2Y12s antiplatelets (tigacrelor, prasugrel) in such patients

Chronic Management of Atrial Fibrillation After ACS

Heidbuchel H. Europace 2013;15:625-51.

Issue Warfarin DOAC

Initial antithrombotic treatment

TAT: ASA 81 mg + clopidogrel + warfarin (INR 2-2.5)

TAT: ASA 81 mg + clopidogrel + reduced-dose DOAC - Dabigatran 110 mg BID - Rivaroxaban 15 mg Qday - Apixaban 2.5 mg BID

Duration of TAT • Elective + BMS= 1 month • Elective + new gen. DES= 6 months*

• ACS and any stent= 6 months*

Special care during TAT

• Frequent monitoring (INR, renal function, CBC ,etc) • Routine gastric protection (pantoprazole or H2 blocker)

ACS= acute coronary syndrome; ASA= aspirin; BMS= bare metal stent; DES= drug eluting stent; DOAC= direct oral anticoagulant; PPI= proton pump inhibitor; TAT= triple antithrombotic therapy

* 1 month only may be considered if bleed risk deemed very high

Lip G, et al. DOI: http://dx.doi.org/10.1093/eurheartj/ehu298 3155-3179

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Issue Warfarin DOAC

After initial 1-6 months of TAT (up to 12 months)

Single antiplatelet therapy (ASA 81 mg or clopidogrel) + Warfarin (INR 2-3)

Single antiplatelet therapy (ASA 81 mg or clopidogrel) + Standard-dose DOAC - Dabigatran 150 mg BID - Rivaroxaban 20 mg Qday - Apixaban 5 mg BID

After 12 months

Warfarin (INR 2-3) Standard-dose DOAC

Lip G, et al. DOI: http://dx.doi.org/10.1093/eurheartj/ehu298 3155-3179

Our patient: CHA2DS2-VASc= 3 HASBLED= 4 ACS

Dashed box= optional therapy

A 71-year-old female on dabigatran 150 mg BID for NVAF (CHA2DS2VASc = 5) was admitted for ACS and emergently taken to the cath lab for percutaneous coronary intervention (PCI). She was found to have multi-vessel disease and had 2 drug-eluting stents placed, which will require dual antiplatelet therapy (DAPT). Her HAS-BLED score is 4.

Which of the following antithrombotic strategies would be recommended for her?

A. Continue dual antiplatelet therapy alone

B. Switch patient to warfarin along with aspirin 325 mg and clopidogrel and continue indefinitely

C. Continue dabigatran at a lower dose along with aspirin 81 mg and clopidogrel for at least a month

D. Continue dabigatran along with aspirin 81 mg and ticagrelor for at least a month

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61 yo F on apixaban for non-valvular afib, involved in rollover vehicle accident on her way to work this morning around 10 AM

Last dose of apixaban was this morning at 8AM

She has multisystem trauma and is hemodynamically unstable

In addition to general approaches to massive hemorrhage, which of the following statements is accurate?

A. Use of FFP will be effective in reversing the apixaban

B. Use of the recently-approved antidote Andexanet-alfa should be employed

C. Use of KCentra® 50 units/kg may be considered for apixaban reversal

D. Dialysis should be initiated immediately to remove the apixaban

Suggest hospitals develop antithrombotic reversal and bleeding management protocols that are easy to access and use in high-stress situations

General approaches for patient on any anticoagulant with major bleed

Withhold anticoagulation

Hemodynamic monitoring

Resuscitation with fluid and blood products

Mechanical compression if possible

Definitive procedural intervention to identify and control bleed

For DOAC patients

Determine which specific DOAC and time of last ingestion

Evaluate patient’s renal function and estimated DOAC t1/2

Rapid lab assessment for clinically relevant DOAC level if possible

If unresponsive to general approaches, consider specific and non-specific antidotes

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Anticoagulant Reversal strategy Mechanism Approval status

Warfarin Vitamin K KCentra® (4-factor PCC)

Overwhelm warfarin inhibition of VKOR-C1 Factor replacement

FDA-approved FDA-approved

Dabigatran (Pradaxa®)

Idarucizumab (Praxbind®)

Monoclonal antibody that binds dabigatran

FDA- approved

Rivaroxaban (Xarelto®) Apixaban (Eliquis®) Edoxaban (Savaysa®)

KCentra® (4-factor PCC)

Factor replacement

Not-FDA approved Use based on very low quality and inconsistent evidence

Andexanet-alfa Decoy Xa molecule Under FDA review

Used for warfarin reversal

◦ Promotes liver synthesis of functional clotting factors II, VII, IX and X

◦ Fat soluble, so effects can linger

Risk of anaphylaxis with IV formulation?

◦ Highly unlikely

IV reduces INR faster than oral formulation ◦ At 24 Hours: oral ≅ IV

Subcutaneous and IM routes are not recommended ◦ SQ= erratic, unpredictable absorption ◦ IM= risk of hematoma formation

Low doses (1-2.5 mg) shown to be equally effective in reducing INR as higher doses (5-10 mg)

DeZee KJ, et al. Arch Intern Med. 2006166:391-397 Watson HG, et al. Br J Haematol. 2001;115:145-149

Crowther MA, et al. Ann Intern Med. 2002;137:251-254

• Often occurs in a non-compressible area

• GI tract

• ICH

• Discontinue warfarin

• IV Vitamin K 10 mg x1 (for sustained reversal)

• Likely that smaller doses could be used

• AND ONE OF THE FOLLOWING (for rapid reversal) • Prothrombin complex concentrate (PCC)

• Fresh frozen plasma 10-30 ml/kg

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0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

Fa

cto

r a

cti

vit

y (%

)

INR

Each unit of FFP increases factor level by 2.5%

At INR of 6, factor level is about 5%

To get to INR of 1.5 (factor level of 40%), need to increase factors by 35%

(40%-5%=35%)

It would require 14 units (~ 3000 ml) of FFP to achieve INR of 1.5

(35%÷2.5%=14)

Yuan et al. Thromb Res 2007; Schulman S. NEJM 2003

14 units FFP

KCentra®

Concentrate of Factors II, VII, IX, X ◦ Also contains Protein C&S, antithrombin III & heparin to mitigate

thrombotic potential ◦ Up to 8% of patients experience thrombotic event

FDA-approved for warfarin reversal in ◦ Life-threatening bleed ◦ Need for emergent surgery

Dose is based on weight and pre-treatment INR ◦ INR 2-3.9= 25 units/kg ◦ INR 4-6= 35 units/kg ◦ INR >6= 50 units/kg

Sarode R, et al. Circulation 2013; 128: 1234-1243

Advantages Disadvantages

Rapid correction of INR

(<30 minutes)

No blood-type matching required

No thawing

Small infusion volume

(40 ml PCC over 15 minutes equivalent ~ 1L FFP)

Possible thrombogenic effects (1.5-8%)

Small risk of blood-borne

viruses (1.9%)

Bershad EM, et al. Neurocrit Care. 2010;12:403‐413

Grobler C, et al. Can J Anaesth. 2010;57:458‐467

Leissinger CA,et al. Am J Hematol. 2008;83:137‐143

Dentali et al. Thromb Haemost. 2011; 106:429-438

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Less common than with warfarin

Less severe than with warfarin (especially ICH)

Drugs have shorter half-life than warfarin

But . . . when it does occur . . .

Psychologically unsettling for provider

Why?

Can’t readily measure

Perception that we can’t reverse

More challenging than warfarin reversal

Patient still has circulating functioning clotting factors

DOACs are a “roadblock” to clot formation

What are our options?

Warfarin Dabigatran Rivaroxaban Apixaban Edoxaban

Target(s) IIa, VIIa, IXa, Xa IIa Xa Xa Xa

Peak effect 4-5 days 1.5-3 h 2-4 h 1-3 h 1-2 h

Half-life 40 h 12-17 h 5-9 h 9-14 h 10-14 h

Renal elimination None 80% 33% 25% 35-50%

Dialyzable No Yes No No Possible

Interactions Many P-gp 3A4, P-gp 3A4, P-gp P-gp

Coagulation

monitoring Yes No No No No

Antidote Vitamin K Idarucizumab No* No* No*

Lab measure INR aPTT

TT, dTT, ECT

PT

Anti-Xa Anti-Xa

PT

Anti-Xa

*andexanet-alfa pending approval

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Potential indications for DOAC measurement

Detection of clinically relevant levels

Detection of expected on-therapy levels

Detection of excessive levels

Urgent or emergent invasive procedure

Assessing adherence Hemorrhage

Neuraxial anesthesia Breakthrough thrombosis

Diminished/changing renal function

Major trauma Hepatic impairment

Potential thrombolysis in acute thromboembolism

Accidental or intended overdose

Hemorrhage Drug interactions

Advanced age

How Should DOACs Be Measured?

Permission of Cuker et al JACC 2014; doi: 10.1016/j.jacc.2014.05.065

Strategy Mechanism

Non-specific

Activated charcoal

Decontamination

Hemodialysis Accelerated elimination (only for dabigatran)

PCC Replacement of factors II, VII, IX, X

rVIIa, aPCC Activated coagulation factors

PER977 Small synthetic molecule

Specific Idarucizumab Monoclonal antibody against dabigatran

Andexanet Recombinant inactive FXa

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• Clinical outcome data on the efficacy of PCC, aPCC and rFVIIa for the reversal of DOACs are lacking

• Available evidence is limited (healthy human volunteers, animal models, in vitro studies) with conflicting results

• These agents may be considered in addition to maximum supportive measures in patients with severe/life-threatening bleeding IF NO ANTIDOTE IS AVAILABLE

• The net clinical benefit should be considered in light of their prothrombotic potential (~ 1.4% for PCC; up to 10% with rFVIIa)

• If necessary, consider 4-Factor PCC (KCentra®) 50 units/kg IV Dentali F. Thromb Haemost. 2011 Sep;106(3):429-38. PMID: 21800002.

Levi M. N Engl J Med. 2010 Nov 4;363(19):1791-800. PMID: 21047223.

Seigal DM, Cuker A. Drug Discov Today 2014. [Epub ahead of print] PMID: 24880102.

Dabigatran

Idarucizumab

Humanized Fab fragment

◦ High-affinity binding specific to dabigatran

Primarily renal excretion

Short half-life

No interaction with other drugs

No intrinsic pro-coagulant or anticoagulant activity

5 mg IV bolus or rapid infusion

Immediate, complete, and sustained reversal of dabigatran

Idarucizumab: Antidote for Dabigatran

Pollack C, et al. N Engl J Med 2015; 373:511-520

1. Shah N et al. AMSRJ. 2014; 1:16-28. 2. Clinicaltrials.gov: NCT02220725. 3. Clinicaltrials.gov: NCT02207725. 4. Positive Results

for Factor Xa Inhibitor Antidote. www.medscape.com/viewarticle/832648. Accessed 10/20/15.

• Engineered version of human FXa, lacking direct catalytic activity of native protein1

• Binds with high-affinity, blocking inhibition of FXa1

P R O P E R T I E S

• Pre-clinical data collected in numerous models1

• Phase 2 dose response assessments in 144 healthy volunteers indicated initial significant, dose-dependent decreases in anti-Xa activity followed by slow increases in anti-Xa activity to high levels1

• 2 studies in healthy subjects aged 50-75 y investigating reversal of rivaroxaban2 and apixaban3

• Phase 3 study in 33 healthy volunteers: “immediately and significantly” reversed anticoagulation of apixaban

• Currently under FDA review

C L I N I C A L D E V E L O P M E N T

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Small molecule

Binds to UFH, LMWHs, Xa inhibitors

No protein binding

No concomitant drug binding

Hemostasis within 10 minutes

Hemostasis for 24 hours

Enriquez, A Europace 2015; Ansell J NEJM 2015

Universal antidote?

rFVIIa (recombinant Factor VII activated)

◦ Not used as much anymore

◦ Single Factor replacement

◦ Higher risk of thrombosis than PCC (does not contain anticoagulants)

Antifibrinolytics

◦ Aminocaproic acid

◦ Tranexamic acid

◦ Prevent clot breakdown by inhibiting fibrinolysis

◦ Risk of thrombosis unknown (appears to be minimal)

DDAVP (desmopressin)

◦ Promotes release of vWF and optimizes platelet function

◦ Often given to patients recently on antiplatelet therapy

aPCC, activated prothrombin complex concentrate; PCC, prothrombin complex concentrate Levy JH et al. Anesthesiology. 2013; Levy JH et al. JACC Interv. 2014.

- Local hemostatic measures - Consider delay or omit next dose or discontinue treatment as appropriate

• Hold all antithrombotics • Mechanical compression • Fluid resuscitation • Hemodynamic monitoring & support • Blood product transfusion • Definitive interventions • Oral charcoal application

(if DOAC ingested <6 hours before) • Hemodialysis (dabigatran only)

• ICU admission • Dabigatran: idarucizumab • FXa inhibitors:

• 4F PCC (50 units/kg) • Adjunctive therapies

• Tranexamic acid • Desmopressin

Patients with bleeding on DOAC

Moderate/severe bleeding

Life-threatening bleeding

Minor bleeding

24

61 yo F on apixaban for non-valvular afib, involved in rollover vehicle accident on her way to work this morning around 10 AM

Last dose of apixaban was this morning at 8AM

She has multisystem trauma and is hemodynamically unstable

In addition to general approaches to massive hemorrhage, which of the following statements is accurate?

A. Use of FFP will be effective in reversing the apixaban

B. Use of the recently-approved antidote Andexanet-alfa should be employed

C. Use of KCentra® 50 units/kg may be considered for apixaban reversal

D. Dialysis should be initiated immediately to remove the apixaban

Thank you

Documents

Allison Burnett, PharmD, CACP, PhC Clinical Assistant ... · Allison Burnett, PharmD, CACP, PhC Clinical Assistant Professor- UNM College of Rx Antithrombosis Stewardship Pharmacist