What’s New in the World of Anticoagulation Angela Lambing, MSN, ANP-c, GNP-c Hemophilia & Thrombosis Treatment Center Henry Ford Health System Detroit, MI Objectives Understand the coagulation cascade and risks of VTE Identify the variety of current anticoagulants available 2012 CHEST guidelines To bridge or not to bridge Disclosures Speaker’s Bureau: GSK Pharmaceuticals Novartis Nursing Advisory Boards Pfizer Baxter Bayer Health Care CSL Behring Octapharma I have no current affiliation or financial arrangement with any grantor or commercial interests that might have direct interest in the subject matter of this CE program Pathophysiology of a Thrombosis Abnormalities of vessel wall atherosclerosis (arterial) trauma, erosion deficient fibrinolysis, venous hypotonia (pregnancy) Abnormalities of blood flow hypertension, turbulence hyper-viscosity stasis, deficient clearance of coagulation factors Abnormalities of blood quantitative platelet abnormalities thrombocytosis decrease of inhibitors, activation of coagulation hypercoagulability Protein C Def, Protein S Def, Antithrombin III Def Vessel wall Virchow’s Triad Statistics Incidence of Venous Thromboembolism exceeds 1 per 1000 cases Over 200,000 cases reported annually in the USA 30% pts die within 30 days of diagnosis 1/5th pts sudden death due to PE 30% survive to develop recurrent VTE within 10 yrs - greatest risk in 1st yr (5-15%) then 1%/yr 28% of cases develop venous stasis syndrome within 20 yrs Heit et al, 2001 Incidence increases with age from 1:1,000 people/year to 1%/year in old age Rosendal,1999 Padua Prediction Score Risk 8 fold risk of VTE 50-75% of VTE events in hospitalized medical pts Hi Risk > 4 Spyropoulos et al. Chest 2011 Heit et al. Arch In Med, 2000 Heit et al. Arch Int Med, 2002 Why Anticoagulate? Thrombosis Arterial Venous Stroke Ineffective management with antiplatelet medications Atrial Fibrillation Cardiomyopathy Prosthetic valves Prophylaxis during cancer therapy Reproduced with permission from: Rao. Am J Med Sci 1998;316:69. How Does Blood Clot - Overview History of Anticoagulants Coumadin© (Warfarin) Advantages: Disadvantages: Inhibits production of Vit K needed for production of thrombin, factors II, VII, IX, X, protein C & S No ceiling to dosing Monitored by INR; 2-3.0 (normal range 0.8-1.2) Dosing amount can decrease with age Inexpensive- 5 mg tabs, #30 = $22.00 Easy to reverse; vitamin K Requires regular blood test monitoring Interactions with multiple medications Can be affected by oral vitamin K food intake Bleeding risk 1%/year long term use Can be difficult to regulate Can cause tissue necrosis if used without concomitant heparin initially after thrombosis Botanicals with Potential Anticoagulant & Interactive Effects with Coumadin©* Alfalfa Dong Quai Arnica ASA Boldo Bucho Cassia Celery Dandelion Fenugreek Horseradish Licorice Nettle Parsley Prickly Ash Quassia Woodruff Tonka Beans Wild Carrot Wild Lettuce Sweet CloverSweet Aniseed Bogbean Capsicum Chamomile Horse Chestnut Meadowsweet Passion Flower Red Clover Bladder Wrack Foetida *Non-exhaustive list ALWAYS check formulary Botanicals than contain Salicylates or Antiplatelet Properties Agrimony Aloe Gel Black Cohosh Black Haw Cassia Clove Feverfew Garlic Gingo Biloba Ginseng Meadowsweet Policosanol Poplar Senega Willow Wintergreen German Sarsaparilla Aspen Bogbean Dandelion Ginger Licorice Onion Tamarind Botanicals with Coagulant Properties Agrimony Goldenseal Mistletoe Yarrow Affected by warfarin Injectable Anticoagulants Enoxaparin (Lovenox©) - LMWH 1 mg/kg Q12, 1.5 mg/kg/day Dalteparin (Fragmin©) - LMWH 200 IU/kg daily Tinzaparin (Innohep©) - LMWH 175 units/kg/day Fondaparinux (Arixtra©) - Direct Anti Xa inhibitor 7.5 mg, sq daily 5.0 mg for < 50 kg 10 mg > 100 kg Renal Dosing Injectable Anticoagulant Properties Advantages: Predictable pharmacokinetic properties and drug interactions Can be effective in recurrent VTE while on warfarin Poor GI absorption not a concern Therapeutic dosage based on patient’s weight Lab monitoring not routinely needed Rapid onset of action and predictable clearance convenient for frequent interruptions due to procedures Disadvantages: Cost Must perform sq injection Difficult to use for patients with decreased GFR Many medical personnel do not understand pharmacokinetics Injectable anticoagulants Anticoagulant ½ life Measurement Lovenox (Enoxaparin©) 12 hours Heparin x assay – 4 hours post injection Fragmin (Dalteparin©) 19 hours Heparin x assay– 4 hours post injection Innohep (Tinzaparin©) 19 hours Heparin x assay– 4 hours post injection Arixtra (Fondaparinux©) 19 hours Arixtra drug trough levels – just prior to next dose **All injectables are cleared through the renal system Affected by UFH Low molecular weight heparins Direct Factor Xa Inhibitor (Arixtra) New Oral Anticoagulants Rivaroxaban --- Xarelto© Affects Xa Hip and knee prophylaxis of DVT Stroke in NVAF November 2, 2012 treatment of DVT/PE Apixaban --- Eliquis© Affects Xa FDA December 2012 to decrease the number of stokes and dangerous blood clots in NVAF Dabigatran --- Pradaxa© Direct Thrombin inhibitor: affects IIa FDA October 10, 2010 approval Stroke prevention in NVAF Pharmacology Characteristic Warfarin© Rivaroxaban Apixaban © Dabigatran © Target Vitamin K factors Factor Xa Factor Xa Thrombin Bioavailability 100% 60-80% 60% 6% Dosing OD OD (BID) BID BID (OD) Time to peak effect 4-5 day 2-4 hours 1-2 hours 1-3 hours Half life 40 hours 7-11 hours 12 hours 8-15 hours Renal clearance None 33% 25% 80% Monitoring Yes No No No Interactions Multiple 3A4/P-gp 3A4/P-gp P-gp © Oral direct thrombin inhibitors Advantages Disadvantages ½ life of 19 hours Oral medication No need for blood testing Side effects: GI upset, diarrhea, Renal clearance of the drug monitor renal/liver function Drug-drug interactions No reversal drug Prothrombin complex concentrates (PCC) Feiba©; Bebulin©, Profilnine ©; FFP, Factor VIIa; Dialysis Lack of understanding mechanism Direct thrombin inhibitors: Arixtra (sq) Dabigatran(PO) Direct Factor Xa Inhibitor: Apixaban Rivaroxaban CHEST Guidelines 2012 ACCP Guidelines: Chest 2012 Patients on vitamin K antagonists (warfarin) undergoing minor dental procedures: Continuation of warfarin around the time of procedure Co-administration of oral pro-hemostatic agents [Grade 1C] ACCP Guidelines: 2012 Patients who require a temporary interruption of a warfarin before surgery and require a normal INR for surgery: Stop warfarin 5 days before procedure (1B) Use of LMWH with last dose 24 hr before surgery at ½ recommended dose (1C) Resume warfarin 12 – 24 hours after surgery (1C) Resume LMWH 24 hr after procedure (1C) ACCP Guidelines: 2012 Mechanical heart valve or atrial fibrillation or current VTE High risk for recurrent VTE; Bridging with therapeutic LMWH of IV UFH Low risk for recurrent VTE: Low dose LMWH or no bridging with LMWH/UFH [Grade 2C] ACCP Guidelines: 2012 Bare metal coronary stent who require surgery within 6 weeks of stent placement: Continuation of ASA and clopidogrel in the perioperative period Drug-eluting coronary stent who require surgery within 12 months of stent placement: Continuation of ASA and clopidogrel in the perioperative period [Grade 2C] ACCP Guidelines: 2012 Patients who require temporary interruption of ASA or clopidogrel before surgery: Stop 7-10 days before procedure Resume agents 24 hours after procedure (2C) CHADS score Indication: Assess risk of stroke with AFib Criteria A. Congestive Heat Failure (1point) B. Hypertension (1 point) C. Age > 75 years (1 point) D. Diabetes (1 point) E. Stroke or TIA history (2 points) Recommendations: CHADS score > 2, consider bridging if on warfarin Gage. Circulation 2004 Bridge Therapy “Shift from oral, long-acting anticoagulants to parenteral, short-acting anticoagulants during sub-therapeutic levels of oral anticoagulant in the perioperative period” Spyropoulos et al. (2004) Bridging Therapy Advantages Provides continued anticoagulation Minimal window without anticoagulation Cost savings for hospitalizations: ~ >$13,000 Disadvantages Use of LMWH for 8-10 days, SQ self injection Plan ahead Prior insurance authorization may be needed Requires coordination of care Can be costly (approx. cost 10 syringes =$600$1,000) Bridging Therapy Process Steps: Lovenox© 1. 2. 3. 4. 5. 6. 7. 8. Hold warfarin 5 days prior to procedure Start LMWH q12h, 4 days prior to procedure Check INR/Platelet level day before procedure Lovenox dose day before procedure in am ½ the usual dose; Hold LMWH night before procedure Restart both warfarin and LMWH q12-24 hr hours after procedure provided there are no signs of bleeding Check INR on the 4th day - goal of INR > 2.0 Stop LMWH when INR >2.0 Expect to be on LMWH for 8-10 days Bridging Therapy Process Steps: Using longer ½ life injectables (Arixtra©) 1. 2. 3. 4. 5. 6. 7. 8. Hold coumadin 5 days prior to procedure Start injectable daily sq, 4 days prior to procedure Last dose of injectable 2 days prior to event (3 ½ lives of the drug) Check INR/Platelet level day before procedure Restart both warfarin and injectable anticoagulant q12-24 hr hours after procedure provided there are no signs of bleeding Check INR on the 4th day - goal of INR > 2.0 Stop injectable anticoagulant when INR >2.0 Expect to be on injectable anticoagulant for 8-10 days Procedure Date Injectable anticoagulant Anticoagulated 5 days ~4-5 days Warfarin Normal Coagulation Check INR Platelet ct Coumadin© induced tissue necrosis Re-initiation of Coumadin© Coumadin© causes decrease of Protein C & S as part of the coagulation system when initially started potentially allows coagulation cascade to go unchecked with increased formulation of thrombin Onset of thrombosis also causes decreases in Protein C & S RESULT: Increases risk of thrombosis Bridging process: oral agents Xarelto©, Pradaxa© Hold 48 hours prior to procedure Restart 12-24 hours after procedure Procedure Date 1 day Anticoagulated 2 days Oral direct thrombin Normal Coagulation Challenges Injectables are now generic Less availability for support programs & educational materials Still costly Insurance approvals Injectables New agents Lack of understanding Medications Testing Interactions Bridging Summary Review risk/benefit of holding any form of anticoagulation Thrombosis vs bleeding risk Individualized treatment Co-ordination of care with: Patients &/or family caregivers Hematology; HTC Anticoagulation clinic Primary physician Monitor patient during process Check INR (as indicated) Bleeding/bruising Platelet count (as indicated) Question #1 Patient is on warfarin for atrial fibrillation Need to extract one tooth Should warfarin be held? Questions to ask….. CHADS score; if high, should not stop warfarin What is latest INR testing?; must be between 2-3 Nature of the procedure…. Increased risks? Question #2 Patient is taking Lovenox© every 12 hours for history of pulmonary embolus History of active colon cancer receiving chemotherapy Pt requires port placement Questions to ask…. Should lovenox be held? How? Question #3 Patient is on Pradaxa© for atrial fibrillation Requires 5 teeth extracted Questions to ask…. CHADS score? Increased risk of VTE? Amount of bleeding? ½ life of the medication Stop Pradaxa© 2 days prior to procedure Restart 12-24 hours after the procedure NO injectable anticoagulant needed Question #4 Pt on long term Arixtra© for history of recurrent VTE Pt history of recurrent VTE on therapeutic warfarin Allergy to Lovenox© itching, rash Needs colonoscopy for Hx of polyps Questions to ask? Hold Arixtra©? How? Angela Lambing, MSN, NP-C Hemophilia & Thrombosis Treatment Center Henry Ford Health System alambin1@hfhs.org 313-916-9094