Newer Oral Anticoagulants and Available Reversal Agents. Cara L. Leos, Pharm D, BCPS AQ Cardiology Baptist Medical Center South Montgomery, AL

Transcription

1 Newer Oral Anticoagulants and Available Reversal Agents Cara L. Leos, Pharm D, BCPS AQ Cardiology Baptist Medical Center South Montgomery, AL

2 Disclosure Speakers bureau Boehringer Ingelheim As each of the newer agents is discussed, they will be presented in order of appearance on the US market, not in any order of personal preforance. We will be discussing 1 investigational new drug

3 Objectives Describe novel anticoagulants and their characteristics Compare differences between new anticoagulants Assess bleeding risk of new anticoagulants Explain different treatment options for bleeding patients Discuss specific reversal agents

4 Your Practice How many of you practice in: A. Community Setting B. Health System Setting C. Other How many are: A. Pharmacists B. Technicians C. Interns

5 Hemostasis Circulatory hemostasis components Vessel walls Plasma proteins / clotting factors Platelets Microparticles / tissue factors Activated by endothelial changes Trauma or injury of some sort Pathological (secondary to certain disease states / physical conditions)

6 Hemostasis Big Picture Reactionary to vascular changes Rapid formation of platelet and fibrin plug at the site of injury During formation, triggers it s own dissolution (fibrinolysis) When normal regulatory systems become overwhelmed: pathologic

7 Thrombosis Pathogenesis Virchow triad Endothelial injury Stasis or turbulence of blood flow Atrial fibrillation Prosthetic heart valves Immobility Blood hyper coagulability Factor V Leiden defect Protein C or S deficiency Antiphopholipid antibody syndrome

8 Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 17 March :02 PM) 2005 Elsevier 8

9 Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 17 March :02 PM) Elsevier

10 Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 17 March :02 10PM) 2005 Elsevier

11 Downloaded from: Robbins & Cotran Pathologic Basis of Disease (on 17 March :02 PM) 11

12 But it s not all about platelets

13

14 Coagulation Factors Procoagulants IIa (thrombin) Ia (fibrin) Xa Va VIIa IXa Anticoagulants Protein C Protein S TFPI t PA Antithrombin (AT)

15 Pop quiz What factors does warfarin inhibit? A. II, V, VII, IX (2, 5, 7, 9), Proteins C & S B. II, V, X (2, 5, 10), Proteins C & S C. II, VII, IX, X (2, 7, 9, 10) Proteins C & S D. Dear Lord, I don t remember. Please make it stop!

16 And in the End

17 When good clots go bad

18 Thrombosis Pathologic response to hemostasis Inappropriate activation of the normal hemostatic processes Formation of a thrombosis in an uninjured vessel Occlusion of the vasculature by thrombis formation after relatively minor endothelial damage

19 Thrombosis Can result in emboli if dislodged Pulmonary embolism Deep vein thrombosis (DVT) Myocardial infarction Stroke Dissolution Fibrinolytic pathway Surgery Drug therapy 19

20 Is it a NOAC or a DOAC?

21 DOAC s on the Market In order of appearance Dabigatran (Pradaxa ) Rivaroxaban (Xarelto ) Apixaban (Eliquis ) Edoxaban (Savaysa )

22 DOAC MOA

23 Current U.S. Indications Stroke prevention in afib All four agents Treatment of venous thromboembolism (VTE) All four agents* Prevention of VTE (surgical) Apixaban, dabigatran, rivaroxaban Secondary prevention of VTE apixaban

24 Direct Thrombin Inhibitor DABIGATRAN (PRADAXA )

25 Dabigatran: afib 150mg PO BID Dose found to be superior compared to warfarin for stroke risk reduction 75mg PO BID if: CrCl 30 50ml/min PLUS dronedarone or ketoconazole CrCl 15 30ml/min (d/c drug if receiving P gp inhibitor) Not to be used in CrCl < 15ml/min

26 Dabigatran and FDA 110mg dose: Found to be non inferior to warfarin for stroke reduction, but less bleeding than the 150mg dose. 110mg dose not FDA approved for afib 75mg dose: Not studied for endpoints in humans Data extrapolated from kinetics models FDA approved

27 Dabigatran: VTE Treatment 150mg PO BID after 5 10days of parenteral anticoag (UFH/LMWH) UFH/LMWH on own for 5 10 days Discontinue UFH/LMWH Start dabigatran at next dose due Safe for CrCl > 30ml/min except: CrCl 30 50ml/min PLUS P gp inhibitors (d/c dabigatran)

28 Dabigatran: VTE Prevention Post op hip replacement surgery 110mg PO X 1 taken 1 4 hours after surgery & hemostasis achieved 220mg PO qday for days If 110mg dose not administered day of surgery, start 220mg regimen on POD 1 Safe for CrCl > 30ml/min except: CrCl 30 50ml/min PLUS P gp inhibitors (d/c dabigatran)

29 Which of the following is TRUE? A. Dabigatran 110mg dose proved superiority over warfarin in stroke reduction secondary to afib. B. Dabigatran can be used in patients on hemo or peritoneal diaylsis C. Dabigatran is now approved post hip and knee replacement in the US D. Dabigatran can be started after the completion of 5 10days UFH/LMWH therapy in acute VTE

30 Dabigatran: Tidbits Cannot be removed from stock bottle during dispensing Need easy off? Pop the top! Unit dose packaging only if to be used in pill boxes Swallow whole! Other administration can result in increased exposure to drug and increased ADE s Will increase an INR

31 Factor Xa Inhibitor RIVAROXABAN (XARELTO )

32 Rivaroxaban: afib 20mg PO qday with evening meal Bioavailability ~ 60% fasting 15mg PO qday with evening meal if: CrCl 15 50ml/min Not to be used CrCl < 15ml/min

33 Rivaroxaban: VTE Treatment 15mg po BID (breakfast/supper) X 21 days, then 20mg po qday with evening meal Provoked VTE: 3 months of therapy Unprovoked: 3 6 months of therapy Can be continued at 20mg po qday for up to years if thought necessary Secondary prevention

34 Rivaroxaban: VTE Prevention Post op hip and knee replacement 10mg po qday (no meal restrictions) Started 6 10hr post op & hemostasis established Knee: days Hip: 35 days Avoid use in CrCl < 30ml/min

35 Rivaroxaban: Tidbits Has some data in extremes of weight Less than 50 and up to 200kg Can be crushed Given in applesauce/pudding Suspended in 50ml H2O & given via feeding tube Still must have food/tube feeds for afib/vte doses immediately after Tablets are not scored Will increase an INR

36 Factor Xa Inhibitor APIXABAN (ELIQUIS )

37 Apixaban: afib 5mg PO BID 2.5mg PO BID if any 2 of the following: Age 80+ Bodyweight 60kg or less SCr 1.5mg/dl + ESRD on HD 5mg po BID 2.5mg PO BID if age 80+ or weight less than 60kg

38 Apixaban: VTE Treatment 10mg PO BID X 7 days, then 5mg PO BID No renal dose adjustment, but patients with SCr 2.5+ or CrCl < 25 were not included in the trials. Clinical decision regarding risk of clot vs risk of bleed. Can be continued at 2.5mg PO BID after 6 months of therapy to reduce secondary clot risk

39 Apixaban: VTE Prevention Post op hip and knee replacement 2.5mg PO BID Started 12 24hr post op Knee: 12 days Hip: 35 days CrCl 15 29ml/min: use with caution CrCl < 15 and dialysis: not recommended

40 Apixaban: Tidbits FOCUS patients 80+!!! These are patients at highest risk for bleeding and are routinely low bodyweight or renally impaired!! Can be crushed Given in applesauce/pudding Suspended in 60ml D5W for feeding tube administration Not dependent on food for absorption Will increase an INR

41 Factor Xa Inhibitor EDOXABAN (SAVAYSA )

42 Edoxaban: afib 60mg PO qday 30mg PO qday if: CrCl 15 50ml/min Do not use in: CrCl < 15ml/min CrCl > 95ml/min!! AUC diminished in normal renal function resulting in potential diminished effectiveness!!! Increased risk of stroke

43 Edoxaban: VTE Treatment 60mg PO qday after 5 10days of parenteral anticoag (UFH/LMWH) UFH/LMWH on own for 5 10 days Discontinue UFH/LMWH Start edoxaban at next dose due 30mg PO qday after UFH/LMWH if: Body weight 60kg or less CrCl 15 50ml/min P gp inhibitors: verapamil, quinidine, azithro /clarithromycin or itra /ketoconazole

44 Edoxaban: Tidbits Only factor Xa inhibitor that can be used with phenytoin or phenobarbital No info regarding feeding tube administration Not food dependent Renal function, renal function, renal function watch your young afib pts! Will increase an INR

45 Which of the following is TRUE? A. Dabigatran needs to be swallowed whole. B. Rivaroxaban & apixaban are safe to use with phenytoin or phenobarbitol C. Edoxaban must be taken with food. D. Rivaroxaban is the only DOAC with dialysis dosing.

46 Comparison of Oral Agents Agent Warfarin Dabigatran Rivaroxaban Apixaban Edoxaban Target IIv, VIIa, IXa, Xa IIa Xa Xa Xa Prodrug No Yes No No No Peak effect 4 5 days 1.5 3hr 2 4hr 1 3hr 1 2hr Half life 40hr 12 17hr 5 9hr 9 14hr 9 11hr Renal elim. None 80% 33% 25% 35 50% Dialyzable No Yes No No No Interactions MANY P gp CYP 3A4, P gp CYP3A4, P gp P gp Monitoring Yes No No No No Antidote Vitamin K, FFP Idarucizumab In study In study In study Cove CL, Hyleck EM. J Am Heart Assoc 2013; 2:e000136

47 Drug in the pipeline Betrixaban Factor Xa inhibitor Currently study: VTE prophylaxis in the medically ill Replacement for LMWH? Inpatient and post discharge while convalescing Estimated market share: 30 million people

48 Therapeutic Drug Monitoring

49 These ain t your momma s warfarin ALL DOAC s increase the INR No relationship to degree of anticoagulation Don t be fooled! Vitamin K isn t going to help PTT: can be used to assess degree of anticoagulation in association with time of last dose

50 These ain t your momma s warfarin Dabigatran aptt (2.5 X reference range) may indicate overanticoagulation Ecarin clotting test (ECT) Academic medical centers Thrombin time (TT) Most reliable (direct thrombin inhibitor) Likely send out lab

51 These ain t your momma s warfarin Factor XaInhibitors Anti factor Xa level Drug/reagent specific ask your lab Values have not been established for DOAC s What levels are therapeutic? How do you adjust?

52 These ain t your momma s warfarin All anticoagulants: CBC Chemistries/renal function AST/ALT Patients should be aware of: Abnormal bruising/bleeding Fatigue, dizziness, shortness of breath

53 Reversal Agents

54 Classics and Bestsellers Vitamin K (PO or IV) FFP (Fresh frozen plasma) Prothrombin Complex Concentrate Factors II, VII, IX, X, proteins C & S Brand name Kcentra None of which has been found effective in DOAC s Dabigatran: hemodialysis

55 Idarucizumab (Praxbind ) Approved for use October 2015 Monoclonal (humanized) antibody for dabigatran Will not work on bivalirudin 5g total infusion (2, 2.5g bottles) Fast onset Use: Need for emergent surgery or life-threatening bleeds

56 Pipeline: Andexanet alfa Modified factor Xa molecule Becomes a decoy for endogenous factor Xa Anticoagulant binds to decoy preventing anticoagulation Will also inhibit actions of enoxaparin and fondaparinux Normally bind to ATIII and potentiate the inhibition of factor Xa

57 Pipeline: Andexanet alfa Phase III trials completed Attempting accelerated approval from the FDA Intended indication: Emergent surgery Life threatening bleed

58 Reversal Agents and Role of Pharmacy Good medication history as possible Last refill, last dose Other potentiating factors including OTC drugs/herbals and antiplatelets Basic PK/PD knowledge Laboratory interpretation Protocol development

59 Case Independent pharmacy medications for a local nursing home Access to basic patient information and all medications provided to the residents. You receive a telephone RX for Mr Smith, a 72yo resident, for vitamin K and the physician wants you to dose it for him.

60 Mr Smith Recently hospitalized for a PE Now on apixaban 5mg PO BID Routine labs resulted today SCr 1.2 CrCl 42ml/min H/H 13.2/38 PT/INR 35.31/3.21 No recent falls or reports of bleeding

61 Mr Smith Based on this information you recommend: A. Vitamin K 5mg IM X 1 B. Vitamin K 1mg IV X 1 C. Vitamin K 2.5mg PO X 1 D. No vitamin K an elevated INR with apixaban is to be expected

62 Case 2 Mrs Rodriguez arrives at the ED where you work. You receive a call from the ED doctor to dose Kcentra. 53yo female on dabigatran 150mg po BID for afib. Last dose yesterday at bedtime PT/INR 82.61/7.51 H/H 12.3/36.9 SCr 2.7; CrCl 42 ml/min

63 Mrs Rodriguez Presenting to the ED with congestion and sinus pressure unrelieved with OTC agents (X 3 days) Denies abnormal bruising/bleeding You quickly review the remaining information available nothing else pertinent

64 Mrs Rodriguez You recommend: A. Kcentra weight based dosing for INR > 6 B. Vitamin K and FFP because that is the recommended treatment in this case C. No action: patient does not meet criteria for dabigatran reversal D. Praxbind 2.5g IV X 2

65 Mrs Rodriguez What if it s 3am and she was instead involved in a motor vehicle accident with her last dose of dabigatran 4 hours ago? She has massive internal injuries and is being taken to the O.R?

66 Mrs Rodriguez You recommend: A. Kcentra weight based dosing for INR > 6 B. Vitamin K and FFP because that is the recommended treatment in this case C. No action: patient does not meet criteria for dabigatran reversal D. Praxbind 2.5g IV X 2

67 Recommended References Acforum.org Free access Guidelines including recent clinical guidance publication Protocols/procedures Webinars monthly on anticoag topics AC Forum Bootcamp information

68 Recommended References Apps Xarelto Anticoag Evaluator (From ACC) MAQI2 Anticoagulation Toolkit Afib Educator

69 Newer Oral Anticoagulants and Available Reversal Agents Cara L. Leos, Pharm D, BCPS AQ Cardiology Baptist Medical Center South Montgomery, AL