1. 1 Quality of anticoagulation and use of warfarin-interacting medications in long-term care Madeleine Verhovsek Bahareh Motlagh Mark A Crowther Courtney Kennedy Lisa Dolovich Glenda Campbell Luqi Wang Alexandra Papaioannou BMC Geriatrics July 2008, 8:13

2. 2 Background Studies have found that warfarin therapy is generally poorly controlled in community settings [Arch Intern Med 1994; 154(17), Arch Intern Med 2000; 160(7)] In long-term care facilities optimal anticoagulation should be achievable : Availability of laboratory monitoring Ensured adherence to warfarin therapy Infrastructure for dose adjustment Ability to detect all potential medication interactions Verhovsek et al. BMC Geriatrics 2008, 8:13

3. 3 Primary Objective Determine how effectively warfarin was administered to a cohort of residents in LTC facilities Secondary Objective Identify the proportion of residents prescribed warfarin-interacting drugs What were the objectives? Verhovsek et al. BMC Geriatrics 2008, 8:13

4. 4 Chart review of 105 residents in five LTC facilities in Hamilton, Ontario All residents were on warfarin therapy Data collected: INR levels Warfarin prescribing and monitoring practices Use of interacting medications What methods were used? Verhovsek et al. BMC Geriatrics 2008, 8:13

5. 5 What are the residents’ characteristics? Percentage of residents on warfarin – 9% Gender - 72% female Mean Age - 83.6 yrs (range 54.7-98.0 yrs) Mean BMI (kg/m 2 ) - 24.9 (range 14.8-37.9) Verhovsek et al. BMC Geriatrics 2008, 8:13

6. 6 How often were residents in therapeutic range? Sub-therapeutic Therapeutic Supra-therapeutic INR: ≤ 1.5 1.6-1.9 2.0-2.5 2.6-3.0 3.1-3.5 ≥ 3.5 Verhovsek et al. BMC Geriatrics 2008, 8:13

7. 7 What about medication interactions? MedicationNo. (%) Acetaminophen Citalopram Acetylsalicylic acid Diltiazem Simvastatin Levofloxacin Phenytoin Ciprofloxacin Sertraline Cotrimoxazole Metronidazole Clarithromycin Amiodarone Amoxicillin-clavulinate Miconazole Propranolol Fluvoxamine 42 (40%) 26 (25%) 17(16%) 12 (11%) 10 (10%) 8 (8%) 7 (7%) 5 (5%) 3 (3%) 2 (2%) 1 (1%) 79% of residents (83 residents) were prescribed at least one interacting drug during period of chart audit Average of 1.8 interacting medications per resident over duration of chart review (range 1-6) 82% of the time (59/72) INR was checked within ≤7 days after initiation of medication or change in dose 72 instances of newly initiated medications or dosage changes Verhovsek et al. BMC Geriatrics 2008, 8:13

8. What did we conclude? 8 INR was in therapeutic range 54.1% of time INR was sub-therapeutic over one-third of time Majority of residents were on medications known to interact with warfarin 20% of the time, INR was not measured within ≤7 days after initiation or change in medication dose Verhovsek et al. BMC Geriatrics 2008, 8:13

9. Acknowledgments This work was funded by : Canadian Institute of Health Research Medical Pharmacies Group Ltd. Regional Medical Associates Verhovsek et al. BMC Geriatrics 2008, 8:13