Oral anticoagulants (p/o) Amboss mainly Flashcards
What are p/o anticoagulants?
vit.K antagonists: warfarin
direct thrombin inhib: dabigatran
direct Xa inhib: apixaban, rivaroxaban, edoxaban
What is direct thrombin p/o inhibitor?
dabigatran
What is direct Xa p/o inhibitors?
apixaban, rivaroxaban, edoxaban
Dabigatran antidote?
Idarucizumab (monoclonal antibody)
Apixaban and rivaroxaban antidote?
andexanet alfa
Management/screening of direct inhibitors p/o?
Regular monitoring of coagulation parameters is not required → improved patient compliance!
Management/screening of warfarin p/o?
Regular monitoring of the PT/INR required (as vitamin K antagonists affect the extrinsic coagulation pathway)
THEREFORE WORSE PATIENT COMPLIANCE
If before procedure is consumed warfarin, what to do?
requires periprocedural bridging anticoagulation
cost of warfarins compared to direct anticoagulants p/o?
wafarin - low cost;
p/o direct - costly
Fibrillation arising from mitral stenosis with a significantly increased risk of thromboembolism (aka valvular AF); Treatment?
coumarins are the only approved treatment
p/o direct (dagibatran; rivarox, apix) - NOT SUITABLE
Indications for all oral anticoagulants?
Prophylaxis of thromboembolism following:
DVT and/or pulmonary embolism
Prolonged immobilization after surgery (e.g., especially in knee or hip surgery)
Nonvalvular atrial fibrillation (for valvular AF - only coumarins)
Expected laboratory changes of warfarin?
Increased PT/INR, no change to PTT or TT (routinely monitored)
Expected laboratory changes of direct thrombin inhib (dabigatran)?
prolonged thrombin time (TT), no change to PTT or PT (not routinely monitored)
Expected laboratory changes of direct factor Xa inhibitors?
prolonged PT and PTT, unchanged thrombin time (not routinely monitored)
The most important side effect of all oral anticoagulants is?
is a dose-dependent increase in bleeding risk
WARsaw is an EXTRaordinary Place To check out: abbreviation?
WARfarin affects the EXTRinsic pathway; therefore, PT should be regularly checked.
WEPT abbreviation?
WEPT: Warfarin Extrinsic pathway PT
warfarin site of action?
liver
warfarin onset of action?
slow
warfarin half time?
longer than heparin
warfarin duration of action?
days
warfarin monitoring?
PT or INR (affects extrinsic pathway)
Heparin route of administration?
i/v; subcutaneous
Heparin site of action?
blood
Heparin onset of action?
rapid
Heparin half time?
shorter than heparin
heparin duration of action?
hours
Heparin mechanism of action?
Activates antithrombin → ↓ action of factors IIa and Xa
heparin monitoring?
PTT (affects intrinsic pathway)