Transcript 0720_Gibson_4D4A2x

Avoiding Complications in
Anticoagulation
Kathleen Gibson, MD
Lake Washington Vascular Surgeons
Bellevue, WA
ACP Annual Congress
Anaheim, CA
November 5, 2016
Disclosures/Acknowledgements
 Consultant for BTG and Covidien, Principal investigator for BTG, Sapheon,
Takeda, Angiodynamics, and Bayer
Complications with Anticoagulation
Over
Anticoagulation
Bleeding
Under
Anticoagulation
DVT
PE
Stroke
Other
Allergy
Other
Keys to avoiding complications
 Choose the right drug for the patient
 Assess for concomitant medications
 Reassess with changes in meds and medical conditions
 Patient education
 Proper monitoring for compliance
 Knowing pharmokinetics and when to hold prior to procedures
Therapeutic agents
 Heparinoids (unfractionated, low molecular weight)
 Vitamin K antagonists (warfarin)
 Direct thrombin inhibitors (dabigatran)
 Factor Xa inhibitors (rivaroxaban, apixaban, edoxaban)
Special considerations
Cancer
LMWH
Pregnancy
LMWH
Breastfeeding
LMWH, warfarin
Renal failure
Avoid dabigatran, rivaroxaban
Hepatic failure
Avoid Factor Xa inhibitors
Heparin-induced
thrombocytopenia
Avoid heparins
Case Study-Right drug/right patient
 84 year old woman with a history of atrial fibrillation
 Presents with a cold, insensate hand for 8 hours
 Was taking dabigatran for stroke prevention
 Duplex shows acute occlusion of the brachial artery
 “Dabigatran failure?”
Case Study-Right drug/right patient
 Further history-grandson obtains prescriptions for patient (she does not
drive)
 Last dose of dabigatran Friday night
 Presents Sunday night
 Short half life of drug and patient dependence on others for help made
dabigatran a poor choice
 DOACs (short half life) require good patient compliance-missed doses can be
unforgiving
Case Study-Concomitant medications
 58 year old man with a history of multiple DVTs and a hypercoaguable state
 Maintained on warfarin for 15 years with INR 2-3
 Develops a gastrointestinal infection with profuse diarrhea and vomiting
 Started on ciprofloxacin with improvement of symptoms
 Presents to ER with severe abdominal and back pain
 Found on CT to have large retroperitoneal bleed
 INR is 8.2
Concomitant meds
 All oral agents can have adverse drug interactions
 Warfarin has the greatest number of interactions (209 major interactions!)
 Patients need to be educated to check with physician/pharmacist when
starting any new medication
 Interactions may increase or decrease effectiveness of blood thinners
 Some may be contraindicated, some may require dose adjustments
Case Study-Change in medical condition
 45 year old man with a history of DVT one month ago
 Treated with Apixaban 5 mg BID
 Develops acute (but likely reversible) liver failure after trip to a 3rd world
country, contracting Hepatitis A
 Has a GI bleed during third day of hospitalization
 Understand drug clearance mechanism, and how changes in kidney and liver
function may influence use of anticoagulants
Case Study-Patient education
 25 year old woman develops a popliteal DVT following knee arthroscopy
 Rivaroxaban 15mg BID (initiation dose) followed by 20mg daily started by ER
 Returns to clinic with chest pain and shortness of breath one week later
 Further workup shows extension of DVT to the common femoral vein, and
subsegmental PE
 Failure of Rivaroxaban?
Case Study-Patient education further history
 Patient reports minimal education in ER
 Continued on oral contraceptive after diagnosis
 Was not taking med with food (rivaroxaban must be taken with food for
proper absorption)
 Was taking 15mg daily (not BID) because remembered ER doc said “this was
a good drug for me because I could take it once a day”
 Patient compliance is dependent on proper education
Case Study-Compliance
 82 year old male with history of multiple DVTs, on chronic warfarin
 Patient has early Alzheimer’s and meds are managed by his wife
 Wife requests to transition to DOAC because of transportation issues
 Transitioned to Apixaban 5mg BID
 Develops new acute DVT after two months
 Apixaban failure?
Case Study-Compliance
 Requested patient’s wife bring “patient’s med box”
 Apixaban had been taken once daily
 Patient on 15 meds-many being taken incorrectly
 Patient placed back on warfarin-ACC keeps INR in proper range
Case study-management around procedures
 10 hours post procedure, developed back pain
 Blood pressure dropped to 70’s systolic with tachycardia
 Hct of 17
 Large retroperitoneal hematoma
 Stabilized with transfusions, activated PCC
 Antiplatelet agents increase risk of bleeding
 Know half lives of all of the agents
Case study-management around procedures
 76 year old woman, takes rivaroxaban for atrial fibrillation
 Admitted for cardiac catheterization for unstable angina
 Rivaroxaban held for 24 hours prior to procedure
 3 stents placed, patient loaded with prasugel
 Groin hematoma after sheath pull, but stable after 2 hours
 Rivaroxaban restarted 6 hours post procedure
Conclusions from my own experience
 Know the drugs
 Know your patients
 Assess patient lifestyle (regular meals, BID v. qd drugs)
 Reassess risk/benefit ratio at least annually for patients on chronic
anticoagulation
Thank you!