1. True or false?

    The action of both heparin AND enoxaparin is dependent on antithrombin.

    In contrast, direct thrombin inhibitors do not require antithrombin for their action.
  2. To which class of drugs does warfarin belong?
    Oral anticoagulants.
  3. What indication is associated with warfarin?
    Treatment and prophylaxis of thromboembolic disorders.
  4. True or false?

    It takes roughly 24 hours before the full therapeutic effect of warfarin is experienced.

    • It takes up to 5-7 days for complete effect.
    • Duration is about 2-5 days.
  5. What is the major and minor enzymatic pathway for warfarin degradation?
    • Major: CYP2C9
    • Minor: CYP3A4
  6. What is warfarin's target MOA?
    Warfarin is a vitamin K analog, and competitively inhibits vitamin K reductase.
  7. What is the function of vitamin K reductase?
    Vit. K Reductase transforms the oxidized form of vitamin K to a reduced form which can then participate in the activation of various clotting factors, including that of Preprothrombin to Prothrombin.
  8. As per warfarin's MOA, what effects does it have on the body?
    Inhibition of the formation of factors II, VII, IX, X, proteins C and S.
  9. What are some adverse effects associated with warfarin?
    • Bleeding
    • Teratogenicity (bone malformations in a fetus occuring from dysfunctional calcium usage)
    • Skin necrosis if warfarin is not carefully initiated (procoagulable state in the first few days of therapy as functioning clotting factors are used up)
  10. What lab parameters should be monitored for the efficacy/toxicity of warfarin?
    PT (and INR?)

    Normal PT is 12-14 seconds
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