BLOOD_GOUT 2 Flashcards
DIRECT THROMBIN INHIBITORS
• Parenteral:
• Oral:
- Parenteral: Lepirudin, desirudin, bivalirudin, argatroban
* Oral: Dabigatran
these drugs inhibit both soluble thrombin and the thrombin enmeshed within developing clots.
DIRECT THROMBIN INHIBITORS
- The protein analogs of ___ bind simultaneously to the active site of thrombin and to thrombin substrates.
- binds solely to the thrombin-active site.
- also inhibits platelet activation.
- lepirudin
- Argatroban
- Bivalirudin
Direct thrombin inhibitors are used as alternatives to ___ primarily in patients with heparin-induced thrombocytopenia.
heparin
Prolonged infusion of lepirudin can induce antibodies that form a complex with lepirudin and prolong its action, and it can induce
anaphylactic reactions
These small molecules directly bind to and inhibit both free factor Xa and factor Xa bound in the clotting complex.
DIRECT ORAL FACTOR Xa INHIBITORS
is approved for prevention of venous thromboembolism following hip or knee surgery and for prevention of stroke in patients with atrial fibrillation.
Rivaroxaban
and other coumarins interfere with the normal post-translational modification of clotting factors in the liver, a process that depends on an adequate supply of reduced vitamin K.
Warfarin
The vitamin K-dependent factors include
- thrombin and
- factors VII,
- IX, and
- X
The effect of warfarin is monitored by the
prothrombin time (PT) test
Used for chronic anticoagulation in all of the clinical situations described previously for heparin, except in
pregnant women
Because warfarin has a ___, its involvement in drug interactions is of major concern.
narrow therapeutic window
↑ warfarin’s clearance and↓ the anticoagulant effect of a given dose.
Cytochrome P450-inducing drugs (eg,
- carbamazepine,
- phenytoin,
- rifampin,
- barbiturates)
↓ warfarin’s clearance and ↑ the anticoagulant effect of a given dose.
Cytochrome P450 inhibitors (eg, - amiodarone, - selective serotonin reuptake inhibitors, - cimetidine)
The thrombolytic drugs used most commonly are either
forms of the endogenous tissue plasminogen activator (t-PA; eg, alteplase) or
- a protein synthesized by streptococci (streptokinase).
is an endogenous fibrinolytic enzyme that degrades clots by splitting fibrin into fragments.
Plasmin
is an enzyme that directly converts plasminogen to plasmin.
Tissue plasminogen activator (t-PA)
is normal human plasminogen activator.
Alteplase