New Oral Anticoagulants. How safe are they outside the trials?

Transcription

1 New Oral Anticoagulants How safe are they outside the trials?

2 Objectives The need for anticoagulant therapy Indications for anticoagulation Traditional anticoagulant therapies Properties of new oral anticoagulants (NOACs) Safety of anticoagulant drugs Sheffield approach Concerns regarding new anticoagulant drugs How to improve safety anticoagulant therapy

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4 Venous Thromboembolism Incidence 1 2 per 1000 per year ~2/3 will present with DVT Pulmonary embolism in >50% of those with DVT Mortality PE 10 25% CTEPH 2 8% Post thrombotic syndrome 50% discolouration, swelling, discomfort 25% pain, ulceration Death in 1 2%

5 AF Related Strokes Nearly 20 30% strokes are cardioembolic AF increases stroke risk 5X in non valvular heart disease 17X in valvular heart disease risk of stroke around 5% / yr Proportion of strokes attributable to AF increases with advancing age % Wolf P et al. Stroke 1991;22;

6 Stroke risk does not predict anticoagulant prescription in clinical practice (y g ) CHADS2 = 0 CHADS2 = 3 CHADS2 = 6 CHADS2 = 1 CHADS2 = 4 CHADS2 = 2 CHADS2 = 5 Journal of Thrombosis and Haemostasis, 6:

7 Improving the health outcomes in patients with AF Not on warfarin: high CHADS 2 risk Not on warfarin: unable to tolerate, intermediate CHADS 2 On warfarin anticoagulation, poor time in therapeutic range

8 Indications for Anticoagulant Therapy Prevention of Venous Thromboembolism (VTE) Treatment of VTE Prevention of Stroke and Systemic Embolism in Atrial Fibrillation (SPAF) Mechanical Heart Valves Acute Coronary Syndromes

9 Mode of Action NOACs

10 Available Anticoagulant Therapies Heparins Vitamin K Antagonists NOACs Unfractionated Heparin Warfarin Dabigatran Low molecular weight heparin Sinthrome (Acenocoumarol) Rivaroxaban Fondaparinux Phenindione Apixaban Edoxaban

11 Oral Anticoagulation 2013

12 Novel Oral Anticoagulants Dabigatran Rivaroxaban Apixaban Half life 12 17h 5 13h 9 12h Administration Oral Oral Oral Renally excreted? +++ +/ +/ Heparin Induced Thrombocytopenia Osteoporosis Side effects Dyspepsia in 8 10% Monitoring? No No No Dietary/ drug interactions Reversal agent????

13 Licensed Indications for NOACS Dabigatran: VTE prevention after elective hip or knee replacement surgery Stroke prevention in Atrial Fibrillation Rivaroxaban: VTE prevention after elective hip or knee replacement surgery Stroke prevention in Atrial Fibrillation Deep Vein Thrombosis treatment and secondary prevention Pulmonary Embolism treatment Acute coronary syndromes Apixaban: VTE prevention after elective hip or knee replacement surgery Stroke prevention in Atrial Fibrillation

14 Dabigatran Warfarin Event rate/100 patient years Major and non major clinically relevant bleeding Major bleeding Life threatening bleeding Intracranial bleeding

15 Rivaroxaban Warfarin Major and non major clinically relevant bleeding Event rate/100 patient years Major bleeding Critical bleeding Intracranial bleeding

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21 Advantages to new anticoagulant drugs Fewer drug interactions Reduced bleeding risk? No monitoring Reliable PK Fewer drug interactions No lifestyle interactions Easier?

22 Drug Interactions with NOACs Increase anticoagulant effect Reduce anticoagulant effect Dabigatran Rivaroxaban Apixaban Amiodarone (caution) Verapamil (caution) Azole antimycotics Tacrolimus Cyclosporin HIV protease inhibitors Dronaderone Rifampicin Carbamazepine Phenytoin Phenobarbital St John s wort Azole Antimycotics HIV Protease Inhibitors Dronaderone Rifampicin Carbamazepine Phenytoin Phenobarbital St John s wort Azole Antimycotics HIV Protease Inhibitors Dronaderone Rifampicin Carbamazepine Phenytoin Phenobarbital St John s wort

23 Disadvantages of new anticoagulants Unsuitable in renal failure Caution in renal impairment (dabigatran) Some drug interactions Increased risk dyspepsia (dabigatran)?increased risk GI bleeding (dabigatran and rivaroxaban) Compliance? Cost

24 Bleeding risk

25 Risk of bleeding on warfarin anticoagulation HASBLED score Pisters et al, CHEST 2010 HASBLED SCORE BLEEDING RISK/100 patient years

26 Bleeding with new anticoagulants Risk of bleeding overall reduced compared with warfarin in studies No head to head studies of new anticoagulants Little real life data as yet Bleeding after surgery Thrombosis of mechanical heart valve Increased bleeding risk in renal failure particularly with dabigatran Antidotes PCC/ Novoseven/ apcc?

27 Compliance Nature of warfarin anticoagulation drives compliance Anticoagulation clinics effective at driving compliance Issues with new anticoagulants? Once daily vs twice daily dosing Nomad boxes

28 Monitoring of anticoagulation Do novel anticoagulants need routine monitoring? Not coagulation testing routinely FBC, renal function testing? How often? Under what specific circumstances might monitoring be useful? Extreme bodyweight, renal impairment, potential drug interactions, bleeding, thrombosis, need for surgery, compliance

29 Dabigatran: Monitoring of NOACs APTT prolonged. Thrombin time prolonged. Haemoclot thrombin inhibitor assay to quantify drug Rivaroxaban: PT variably prolonged (depends on lab reagents) Anti Xa assay to quantify drug Apixaban: PT variably prolonged Anti Xa assay to quantify drug

30 Sheffield Approach VTE prevention Medical patients LMWH whilst IP unless contraindication Surgical patients LMWH whilst IP unless contraindication Extended LMWH prophylaxis abdominal/pelvic cancer surgery Orthopaedics hip and knee arthroplasty LMWH whilst inpatient, rivaroxaban after discharge Orthopaedics lower limb casts Rivaroxaban in those at high risk (or LMWH if cancer/ pregnant)

31 Treatment of DVT NICE 2012 Offer a choice of LMWH or fondaparinux Consider UFH if renal impairment Warfarin target INR 2.5 for minimum 3 months Continue LMWH for minimum 5 days or until INR >2 for at least 24 hours Offer LMWH to patients with cancer and continue for at least 6 months Class 2 ECS reduce risk Post Thrombotic Syndrome Consider continuing warfarin beyond 3 months if idiopathic or recurrent thrombosis and considered at low risk of bleeding In practice all those with idiopathic thrombosis at STH have 6 months treatment UNLESS high bleeding risk. Investigate those with idiopathic thrombosis over the age of 40yrs for malignancy

32 NICE Rivaroxaban HTA 261 Rivaroxaban is recommended as an option for treating deep vein thrombosis and preventing recurrent deep vein thrombosis and pulmonary embolism after a diagnosis of acute deep vein thrombosis in adults

33 NORCOM primary care flowchart for the prevention of stroke and systemic embolism in Non Valvular Atrial Fibrillation CHADS2 score (see appendix 2) Consider specialist opinion Consider aspirin 0 Yes and CHADS2 score 1 Yes and CHADS2 score 1 1 or more Consider warfarin first line Is warfarin contraindicated or is patient unable to manage variable dosing with appropriate support? No; start warfarin. Target INR 2.5 HASBLED 3 (see appendix 2). Note benefit may still outweigh risk in many patients Yes and CHADS2 score 2 or more Yes and CHADS2 score 2 or more Consider rivaroxaban, if switching from warfarin check INR and start rivaroxaban if INR 3 (AF only) Once INR stabilised: Is the INR outside on 2 occasions in a six month period or over 8 on one occasion? No If rivaroxaban not suitable consider dabigatran (once INR<2, if switching from warfarin) or seek specialist opinion Continue Warfarin

34 Atrial Fibrillation Summary Anticoagulate (not aspirin) Warfarin first line for most Initiate and monitor warfarin If stable (TTR > 65%, no unexplained INRs >5, no consecutive INRs <1.8), continue warfarin If unstable (unexplained INR >5.0, consecutive INRs <1.8, poor TTR), switch to Rivaroxaban If side effects, unable to manage instructions, switch to Rivaroxaban

35 Incidents it s a NSAID isn t it? VTE prophylaxis with new anticoagulant it s OK, it s an anticoagulant On prophylactic dose new anticoagulant, presenting with VTE, therapeutic anticoagulation not started Surgical issues Lack of recognition anticoagulant Renal impairment failure to clear drug before surgery

36 Introducing New Anticoagulants into your Service Patient assessment and choice What anticoagulant is appropriate for the patient? Trial of warfarin? Renal function/ liver function/ anaemia? Interacting drugs? Patient counselling Compliance Bleeding risk Start medication Documentation (?CDSS system) Monitoring

37 How to improve safety of new anticoagulants Clear guidelines Checklists and decision support documentation Appropriate indication? Interacting drugs? Baseline investigations Anaemia? Renal failure? Regular medicines review and reinforcement compliance Monitoring? FBC and renal function? Audit practice

38 Soap Box Issues Safe systems must be in place Education, education, education Staff and Patients Guidelines for surgery and emergency reversal Communication particularly at primary / secondary care interface Compliance and bleeding risks Patients need reminding if risks to be minimised Sits well with primary care chronic disease management

39 Looking to the Future As experience grows with new oral anticoagulants, clinicians will become more experienced with their use Reduction in inappropriate use (interacting medications, renal failure) More data available re: reversal better protocols developed Familiarity increased in healthcare setting Increasing prevalence of AF and VTE Lower risk of bleeding with new therapies will shift risk:benefit equation Costs of new therapies Review of services monitoring warfarin anticoagulation What will anticoagulation services look like? Warfarin dosing? Anticoagulation management? Need to retain staff competencies to manage patients receiving warfarin anticoagulation

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