Transcript Preventing Anticoagulation Errors with Clinical Dashboards

Preventing Anticoagulation
Errors with Clinical Dashboards
Dan Johnson, Pharm.D., BCPS
August 3, 2011
Objectives
• Describe the anticoagulant dashboards
• Summarize the common anticoagulant drugs
and their dashboard alerts
• Discuss future directions in anticoagulant
therapy and monitoring
Medication Errors with
Anticoagulants
• Significant potential for
harm at normal doses
• Minimal room for error
with anticoagulants
• Always read labels
carefully
• Monitoring is critical to
prevent adverse events
Using Clinical Dashboards
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What is a “dashboard”
Alert values for various drugs
Concurrent monitoring of target drugs
Focus on “at risk” patients when we cannot
follow every patient
• Resolve alerts and communicate information
w. providers and other pharmacists
Anticoagulant Drugs
• Heparinoids
– Unfractionated heparin (UFH)
– Enoxaparin (Lovenox®)
• Coumarin derivatives
– Warfarin (Coumadin®)
• Direct Thrombin Inhibitors
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Argatroban
Lepirudin (Refludan®)
Bivalirudin (Angiomax®)
Dabigatran (Pradaxa®)
• Factor Xa Inhibitors
– Fondaparinux (Arixtra®)
– Rivaroxaban (Xarelto®)
Unfractionated Heparin
• Indirectly inhibits thrombin by binding to
antithrombin III
• Large molecule with significant variability
• Pharmacokinetics change based on dose
– Half-life increases as dose increases
• Where does heparin come from?
Pig Guts!!!
VUH Heparin Protocols
• Three main protocols
– Lower dose (ACS, atrial fibrillation, etc.)
– Higher dose (DVT, PE, etc)
– Custom
• Nurses manage lower and higher dose
protocols on implemented floors
• Providers manage the custom protocol
• Each protocol has limitations
Heparin Protocol-Items ordered
Higher Dose Heparin Protocol
Enoxaparin (Lovenox)
• Shorter molecule of heparin
– Low molecular weight heparin vs. UFH
• Predictable pharmacokinetics
– Does not vary by dose
• Simple dosing
• Administered subcutaneously
• No monitoring required
– Anti-Xa levels may be used in rare situations
• 4 hours post dose, 0.6 to 1 for q12h treatment doses
Concerns with Enoxaparin
• Adverse events similar to heparin
– Bleeding
– Thrombocytopenia
• Lack of monitoring around invasive
procedures
• Epidural anesthesia
– Black box warning
• Dosing in obese patients
• Renal dosing for CrCl<30 ml/min
Heparin-induced Thrombocytopenia (HIT)
• HIT Type 1 (HAT)
– Non-immune mediated
– Usually do not drop platelets < 100,000
• HIT Type 2 (HITTS)
– IgG antibody against heparin-PF4 complex
– Onset 3-15 days after starting heparin
– 50% drop in platelet count
– Associated with thrombosis
Treatment and Diagnosis
• Diagnosis
– ≥ 50% drop in platelets
– HIT antibody test
– Serotonin release assay
• Treatment
– Remove all sources of
heparin!!!
– Heparin allergy
– Alternative
anticoagulant
• Direct thrombin inhibitor
• Fondaparinux
Heparin Dashboard
Alert Values for Heparin
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Platelet drop
HIT positive
Old PTT/no PTT
CrCl< 30 ml/min
Infusion >2,500 units per hour
Evaluating a Dashboard Alert
Communicating Information Forward
Dashboard Functionality
• Alerts are addressed by clinical pharmacists in
each patient care area
• Single pharmacist each daily responsible for
final sign off
• Clinical pharmacists & pharmacy residents
have primary dashboard responsibilities
Warfarin (Coumadin)
• Oral anticoagulant drug
• Inhibits vitamin K dependent clotting factors
– Dietary vitamin K
• Where does warfarin come from?
– Rat poison
• Indicated for long term anticoagulation
– Stroke prevention
– DVT/PE
– Mechanical heart valves
Good Old Warfarin
• Slow onset (3-5 days)
• Numerous drug
interactions
• Dietary concerns (Vit. K)
• Unpredictable dosing
• Frequent monitoring
• Procedural bridging
• Complicated patient
counseling
• Limited alternatives
Warfarin Monitoring
• Signs of bleeding
– Monitor CBC
• Monitor INR for clinical efficacy and safety
– Normal INR 1
– Therapeutic INR 2-3 for most
– Bleeding risk increases as INR goes up
– INR should increase by 0.2-0.3 per day
– Dose changes by 10-20%
Warfarin Dashboard Alerts
• Rapid rise in INR (>0.4 in 24 hours)
• High INR (INR >3)
• Old INR/No INR
Warfarin Dashboard
Warfarin Patient Details
Challenges with Dashboard
Monitoring
• Staffing
– Experience
– Weekend/afterhours coverage
– Practice variations
• Developing quality alert values
– Garbage in, garbage out
– Alert frequency
– Positive predictive value
• Informatics resources
The Future of Anticoagulation
• Oral direct thrombin inhibitors
– Dabigatran (Pradaxa)
• Oral Factor Xa inhibitors
– Rivaroxaban
– Apixiban
– Betrixaban
• Several potential benefits:
– Less variability
– Oral administration
– No monitoring required
Dabigatran (Pradaxa)
• Oral, fixed dose direct thrombin inhibitor
– 150 mg twice a day
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Predictable pharmacokinetics
Quick onset, relatively short duration
Limited drug interactions, no dietary concerns
No monitoring required
Dabigatran (Pradaxa®)
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Oral direct thrombin inhibitor
Rapid onset
Short duration of action
Fixed dosing
No routine monitoring required
Limited drug interactions
No drug-food interactions
Concerns with Dabigatran
• Renal clearance
– Dose adjust for CrCl <30 ml/min
– 75 mg BID
– Do not give if CrCl <15 ml/min
• Inability to monitor around invasive
procedures
• Capsules must be swallowed whole
• No reversal agent
• Cost
Why Use Dabigatran?
• Indicated for non-valvular atrial fibrillation
– Better than warfarin
– Non-inferiority data in VTE
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Inability to achieve stable INR on warfarin
Easier transition to oral anticoagulant therapy
Procedural bridging may be easier
Rapid onset compared to warfarin
Patient must be able to afford dabigatran
When to Avoid Dabigatran
• Renal failure
• Indications without data for dabigatran
– Mechanical heart valves
– VTE prophylaxis
– Heparin-induced thrombocytopenia
• Cost concerns with dabigatran
• Stable warfarin patients?
• Can pharmacogenomics make warfarin dosing
easier/better?
Rivaroxaban (Xarelto)
• Oral factor Xa inihibitor
• FDA approved for ortho prophylaxis
– 10 mg daily
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Take with or without food
Substrate of CYP P450 3A4 and pGP
Avoid use if CrCl <30 ml/min
Half life 5-9 hours
Per tube administration may reduce
bioavailability
Rivaroxaban Dosing
• Ortho prophylaxis
– 10 mg once daily starting 6 to 10 hours after
surgery
– Only FDA approval at this point
• DVT/PE
– 15 mg BID for 3 weeks followed by 20 mg daily
• Atrial fibrillation
– 20 mg once daily, 15 mg daily for moderate renal
impairment
Future Directions
• Improve dashboard functionality
– New alerts (old drugs and new)
– Newer monitoring systems (Sentri7)
• Utilize new anticoagulants in appropriate
patients
• Clinical pharmacist focusing on only
anticoagulation
• Inpatient anticoagulation service
Questions?