Nibal R. Chamoun, Pharm.D., BCPS Clinical Assistant Professor of Pharmacy Practice at the Lebanese American University Clinical Pharmacy Coordinator

Transcription

1 Nibal R. Chamoun, Pharm.D., BCPS Clinical Assistant Professor of Pharmacy Practice at the Lebanese American University Clinical Pharmacy Coordinator at LAUMCRH

2 Review the mechanism of action, indications and contraindications of new oral anticoagulants Identify patients who may benefit from the new oral anticoagulants Discuss available monitoring and reversibility of NOACS Discuss important counseling tips & initiatives to consider

3 AC: Anticoagulation NOACS: Novel oral anticoagulants SPAF: Stroke prevention in Atrial Fibrillation VTE: Venous thromboembolism DVT: Deep venous thrombosis PE: Pulmonary embolus Hb/Hct: hemoglobin/hematocrit PK and PD: pharmacokinetic and pharmacodynamic

4 Saraf K, et al. Postgrad Med J 2014;90:

5 impairment VKAS (ACENOCOUMAROL, HYDROXYCOUMAROL) Variability in dosing More monitoring Long half life Numerous drug/food interactions NOACS ( RIVAROXABAN, DABIGATRAN, APIXABAN) Fixed dosing Less monitoring Shorter half lives compliance is important Less drug food interactions Dosage adjustment required for renal

6 Dabigatran Rivaroxaban Apixaban Available in Lebanon Yes Yes Soon! CHEST 2012; 141(2)(Suppl):e120S e151s Target Thrombin Factor Xa Factor Xa Bioavailability Frequency Bid Bid or daily bid T- max (h) Half life (h) Protein binding(%) CYP metabolism (%) None P-gp transport Yes Yes yes Renal excretion (%) Non renal excretion(%)

7 CHEST 2012; 141(2)(Suppl):e24S e43s Oral Anticoagulant Routine laboratory test Other monitoring parameters VKA Antagonists PT/ INR LFTs Oral DTI (Dabigatran) No routine test SrCr Direct Xa inhibitor (Rivaroxaban) No routine test SrCr Direct Xa inhibitor (Apixaban) No routine test SrCr

8 Stroke prevention in Atrial Fibrillation (SPAF) Treatment of VTE (PE and DVT) Thromboprophylaxis in orthopedic patients

9 Stroke prevention in Atrial Fibrillation (SPAF) Treatment of VTE (PE and DVT) Thromboprophylaxis in orthopedic patients

10 MM is a 67 year old woman who underwent a mechanical mitral valve replacement 7 months ago. She presents to clinic with atrial fibrillation and during work up expresses interest in being started on rivaroxaban instead on acenocoumarol. Creatinine Clearance ~ 90ml/min. At home is on: acenocoumarol regimen: MWFSS 2mg & TTH 3mg INR goal Last INR ( 1 week ago, 2.7) Which of the following is the best treatment plan for this patient? A. Switch to rivaroxaban 20mg po daily B. Switch to rivaroxaban 15 mg po daily C. Switch to dabigatran 150mg po bid D. Keep on acenocoumarol

11 Data randomized controlled trials (~ 70,000 patients) Majority are non-inferiority trials in terms of decrease in stroke (Ischemic & hemorrhagic) in comparison to VKA Less incidence of intracranial hemorrhage NOACs are associated with an increase in GI bleeds as compared to warfarin

12 Non-valvular atrial fibrillation + Indication for Anticoagulation Dose adjustments of NOACS are necessary for renal impairment in Stroke Prevention in Atrial Fibrillation (SPAF)

13 RELY ROCKET-AF ARISTOTLE Two doses studied 150mg PO BID 110mg PO BID 20mg po daily reduced to 15 mg po daily 5mg po BID reduced to 2.5mg po BID Not studied in CrCl< 30ml/min Approved on the market is also 75mg po BID If CrCl30-50 ml/min If ANY TWO: If age 80 years If weight 60kg If SrCr 1.5mg/dl

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15 N= 256 patients Terminated early: The use of dabigatran in patients with mechanical heart valves was associated with increased rates of thromboembolic and bleeding complications, as compared with warfarin, thus showing no benefit and an excess risk. N ENGL J MED 369;13 september 26, 2013

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17 Valvular Indications and Contraindications to NOACs in Afib Contraindicated for NOACS Mechanical prosthetic heart valves Mitral stenosis(moderate to severe) Eligible for NOACS Other native valve diseases (mild to moderate) Severe aortic stenosis Bioprosthetic heart valves (except in the first 3 months) Mitral valve repair (except in the first 3-6 months) Europace doi: /europace/euv309

18 Europace doi: /europace/euv309

19 Mechanism of interaction: cytochrome P450 3A4 and P- glycoprotein (P-gp) Concern: minimal guidance for dose adjustments & monitoring is not possible Interacting medications: Antimicrobials (antifungals, antibiotics, antiretrovirals) Antiepileptics Immunosuppressant Verapamil

20 Contraindicated medication Verapamil Protease inhibitors Cyclosporin Tacrolimus Itraconazole Ketoconazole Posaconazole Voriconazole Fluconazole- unknown Reason for contraindication Increases levels by % Increase levels- unknown Increases levels by % Dosing suggested by US labeling If normal renal function, consider dosing at 110mg po BID instead of 150mg po bid US labeling: 75 mg PO BID if CrCl 30-50ml/min Rifampicin Carbamazepine Phenobarbital Phenytoin Lower dabigatran levels by 66% Europace. European Heart & Rhythm Association doi: /europace/euv309

21 Approved for non-valvular atrial fibrillation Imperative to dose adjust in renal dysfunction Less intracranial hemorrhage but more gastrointestinal bleeding ( except apixaban) Necessitate that pharmacists screen for drug interactions

22 MM is a 67 year old woman who underwent a mechanical mitral valve replacement 7 months ago. She presents to clinic with atrial fibrillation and during work up expresses interest in being started on rivaroxaban instead on acenocoumarol. Creatinine Clearance ~ 90ml/min. At home is on: acenocoumarol regimen: MWFSS 2mg & TTH 3mg INR goal Last INR ( 1 week ago, 2.7) Which of the following is the best treatment plan for this patient? A. Switch to rivaroxaban 20mg po daily B. Switch to rivaroxaban 15 mg po daily C. Switch to dabigatran 150mg po bid D. Keep on acenocoumarol

23 Stroke prevention in Atrial Fibrillation (SPAF) Treatment of VTE (PE and DVT) VTE Prophylaxis in orthopedic patients

24 Randomized controlled trials (~ 25,000 patients) Non-inferior to conventional treatment for VTE recurrence(margins of non-inferiority between ) Less bleeding (notably more GI bleeding, except apixaban) Superior to placebo for the prevention of recurrent VTE and are associated with lower bleeding rates. J Thromb Thrombolysis (2015) 39: Blood 2014;124(7):

25 2012 ACCP Guidelines NOACs (dabigatran and rivaroxaban) as an option Provides weak recommendation in favor VKA/parenteral anticoagulation(conventional treatment) 2014 ESC Guidelines NOACS as alternatives to conventional anticoagulation for the acute treatment, first three months and extended treatment(>3 months) Konstantinides et al. European Heart Journal. doi: /eurheartj/ehu283 CHEST 2012; 141(2)(Suppl):e419S e494s

26 A 70 yo woman (wt=80kg, ht=173cm) is diagnosed with a DVT. No significant PMH. Pertinent history is that she s not very active and had recent travel. Her CrCl is estimated at 25ml/min. Which of the following treatment choices is most suitable for this patient? A. Enoxaparin that is bridged to acenocoumarol 2mg po daily B. Rivaroxaban 15mg po BID for 21 days followed by 20mg po daily C. Enoxaparin for 7 days followed by Dabigatran 150mg po BID D. Dabigatran 150mg po BID

27 DVT or PE + Good renal function defined as CrCl( 30 ml/min) NO DOSE ADJUSTMENTS EXIST for CrCL < 30ml/min for Apixaban, Dabigatran or Rivaroxaban in the treatment of VTE

28 Management Strategies Bridging: Parenteral anticoagulant + bridge to oral therapy VKA Directly oral treatment: Rivaroxaban 15mg PO BID for 21 days, followed by 20mg PO daily Apixaban 10 mg PO BID for 7 days followed by 5 mg PO BID Switching: Start parenteral anticoagulant for 1-2 weeks, then switch to Dabigatran 150mg PO BID Start parenteral anticoagulant, then switch to Edoxaban 60mg po daily or if impared renal function (CrCrl 30-50ml/min, weight<60kg or taking potent pgp inhibitors) 30mg PO daily

29 Blood 2014;124(7):

30 Blood 2014;124(7):

31 Patients who should NOT receive NOACS Severe renal impairment defined as: CrCl<30 ml/min for rivaroxaban, dabigatran and edoxaban; and <25 ml/min for apixaban VTE in the setting of Cancer VTE in the setting of thrombophilic conditions When compliance is a concern Blood 2014;124(7): Konstantinides et al. European Heart Journal. doi: /eurheartj/ehu283

32 Patients who should NOT receive NOACS History of GI bleeds Nursing mothers Pregnancy Extreme body weight Blood 2014;124(7): Konstantinides et al. European Heart Journal. doi: /eurheartj/ehu283

33 Appropriate candidates for NOACS On VKA antagonists with erratic INRs Those who find INR testing burdensome Reliable and compliant patients Blood 2014;124(7):

34 Patient specific criteria Prefers to avoid injections CrCl between ml/min Dyspepsia or GERD NOAC selection Apixaban or Rivaroxaban Apixaban, rivaroxaban, edoxaban (not dabigatran) Rivaroxaban, apixaban, edoxaban Recent GI bleed Poor compliance with twice daily dosing Recent myocardial infarction Apixaban Rivaroxaban or edoxaban Rivaroxaban, apixaban,edoxaban Blood 2014;124(7):

35 NOAC US Dosing European Dosing Dabigatran After 5-10 days of parenteral Rivaroxaban 150 mg PO BID (caution with pgp inhibitors and in elderly patients) 15 mg PO BID for 3 weeks, followed by 20mg PO Daily Apixaban 10 mg PO BID for 7 days, followed by 5 mg PO BID (once 6 months have been given, switch to 2.5 mg PO BID for extended treatment) Edoxaban After 5-10 days of parenteral 60 mg po daily Patient weight 60 kg: 30 mg PO daily specific P-gp inhibitors (ie, verapamil, quinidine; azithromycin, clarithromycin, erythromycin, itraconazole, ketoconazole): 30 mg once daily 150 mg PO BID or 110 mg PO BID for patients >80 years of age or on verapamil 15 mg PO BID for 3 weeks, followed by 20mg PO Daily 10 mg PO BID for 7 days, followed by 5 mg PO BID 2.5 mg PO BID for extended treatment Lexicomp 2015 Konstantinides et al. European Heart Journal. doi: /eurheartj/ehu283

36 Interacting medications: Antimicrobials (antifungals, antibiotics, antiretrovirals) Antiepileptics Immunosuppressants Verapamil Amiodarone In general, avoid NOACs with interacting medications in VTE treatment Adjustments based on PK and PD analyses Not studied in the clinical setting of VTE Edoxaban was actually studied to account for dose adjustments in VTE (Dabigatran):EPARProduct Information ;(Apixaban):EPARProduct Information ;(Rivaroxaban) :EPAR Product Information

37 Verify appropriate renal function CrCl> 30ml/min Screen for interactions & caution providers Remember the strategies: Start directly oral therapy with Rivaroxaban or Apixaban If dabigatran or edoxaban are selected, the first week should be parenteral treatment, then SWITCH to NOACS Avoid in special populations: cancer, pregnancy, thrombophilic conditions, extreme body weight Emphasize on compliance, especially the switch in doses

38 A 70 yo woman (wt=80kg, ht=173cm) is diagnosed with a DVT. No significant PMH. Pertinent history is that she s not very active and had recent travel. Her CrCl is estimated at 25ml/min. Which of the following treatment choices is most suitable for this patient? A. Enoxaparin that is bridged to acenocoumarol 2mg po daily B. Rivaroxaban 15mg po BID for 21 days followed by 20mg po daily C. Enoxaparin for 7 days followed by Dabigatran 150mg po BID D. Dabigatran 150mg po BID

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40 Questions to consider asking Dose of the NOAC Time of last dose with respect to renal function Usually takes hours for the drug to be out of the system if >12 h possible to wait for the drug to clear while monitoring and managing with supportive care Factors influencing plasma concentrations Any P-gp therapy, cyp inhibitors, CKD, renal function Baseline Hct/Hb and platelet count

41 Factors to consider: CrCl, half life & bleeding risk Renal function (CrCl ml/min) Half-life (hours) Timing of discontinuation after last dose of dabigatran before surgery Standard risk of bleeding High risk of bleeding (major surgery, spinal procedure or placement of epidural or spinal cath) >80 13 (11-22) 24 h 2-4 days >50 to (12-34) 24 h 2-4 days >30 to (13-23) 48h 4 days (22-35) 2-5 days >5 days Thrombosis and Haemostasis 103.6/2010 Pradaxa (Package Insert). Ridgefield, CT: Boehringer Ingelheim Pharmaceuticals,Inc2010

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43 Agents Target Structure Route MOA Idarucizumab FDA approval on for Emergency Reversal Dabigatran Humanized monoclonal antibody fragment IV Binds to Dabigatran with a high affinity (~350 times > thrombin) Andexanet alfa fxa inhibitors Modified recombinant from of fxa IV Binds to fxa inhibitors with affinity similar to that of native fxa Aripazine (PER 977) Universal -fxa inhibitors -Dabigatran -UFH, LMWH Small synthetic molecule IV Binds to oral anticoagulants and heparin and reverses the anticoagulant effects Mo Y. Pharmacotherapy 2015;35:201. Ansell JE, et al. N Eng J Med 2014:371:

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45 Involve your patient Compliance frequency of medication Importance of follow up even if no INR checks Inform the doctor about new medications Missed doses How to take the medication How to store the medication In case of bleeding, share with physician time of last dose and renal function

46 Dabigatran Do not crush or chew tablets Do not open or sprinkle the capsule Avoid in patients with GERD, history of GI bleed, MI Rivaroxaban Take with food You can crush tablets Avoid in history of GI bleed Apixaban You can crush tablets

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51 NOACS have provided a significant advancement in oral anticoagulation Appropriate patient selection is mandatory SPAF: non-valvular atrial fibrillation and dose adjust for renal impairment VTE: renal impairment is a contraindication, no dose adjustments are available

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