Heparin, warfarin, direct oral anticoagulants, and antiplatelet drugs with mechanism of action, distinct from the monitoring and antidote focus of the Nursing Pharmacology anticoagulants deck.
40 cards · basic cards · AI-written, checked twice. Edit anything.
- What plasma protein does unfractionated heparin activate to exert its anticoagulant effect?
- Antithrombin III (antithrombin)
- Which two clotting factors does heparin-activated antithrombin III primarily inactivate?
- Thrombin (factor IIa) and factor Xa
- What is the route of administration for unfractionated heparin?
- IV or subcutaneous injection, not oral
- Heparin binds antithrombin through a unique ____ sequence, greatly accelerating antithrombin's activity.
- pentasaccharide
- Name two low molecular weight heparins.
- Enoxaparin and dalteparin
- Compared to unfractionated heparin, low molecular weight heparin preferentially inhibits which factor?
- Factor Xa, with much less effect on thrombin
- Why does LMWH have less effect on thrombin than UFH does?
- Its shorter chains are too short to bridge antithrombin to thrombin at the same time
- What is fondaparinux?
- A synthetic pentasaccharide that selectively inhibits factor Xa through antithrombin
- Does fondaparinux have any direct effect on thrombin?
- No, it is selective for factor Xa
- Warfarin's mechanism of action
- Inhibits vitamin K epoxide reductase (VKORC1)
- Warfarin's inhibition of vitamin K epoxide reductase prevents ____ of vitamin K-dependent clotting factors.
- gamma-carboxylation
- Which four clotting factors have reduced synthesis due to warfarin?
- Factors II, VII, IX, and X
- Besides clotting factors, which two natural anticoagulant proteins does warfarin also reduce?
- Protein C and protein S
- Why does warfarin have a delayed onset of anticoagulant effect after starting therapy?
- Already-circulating clotting factors must degrade according to their own half-lives first
- Why can warfarin cause a transient hypercoagulable state early in therapy?
- Protein C has a short half-life and falls before the procoagulant factors do