Pulm: Drugs used for PE/DVT Flashcards
MOA of Heparin
Long polysaccharine that binds and activates ATIII to inhibit Factors Xa and IIa
Rapid onset in treating Red Clots in PE, stroke, DVT, DIC
Which is rapid onset: Heparin or Warfarin?
Heparin
Is heparin safe in pregnancy?
Yes, “Keep your baby Heppy with Heparin”
What is the antidote to heparin or Low Molecular Weight Heparin (LMWH) OD?
Protamine
What do you monitor with heparin and warfarin?
Heparin: PTT
Warfarin: PT
-war takes place outside, extrinsic
What are contrainidcations for all the drugs used for DVT?
Bleeding (hemophilia/thrombocytopenia) and stroke
What drugs are LMWH?
Enoxaparin, Delteparin, tinazeparin
MOA of LMWH?
Inhibits Xa, prevents red clots
-little effect on existing thrombin
Clinical use of LMWH
Prevention of DCT after knee/hip surgery
Treatment of DVT w/ or w/o PE history
Prevention of ischemic events in ACS
Is enoxaparin safe in pregnancy?
Yes
Which is more reliable, LMWH or heparin?
LMWH is easier to use, has a longer half life, and is now the first choice to prevent DVT
MOA of fondaparinux
Binds Xa, preventing II->IIa
Which one is more effective, fondaparinux or LMWH?
Fondaparinux is more effective, but bleeding risk is higher
How do you administer fondaparinux?
SubQ Everyday
-long half life (too long?)
Clinical applications of fondaparinux
Prevention of DVT
Acute PE with warfarin
Acute DVT with warfarin
Is fondaparinux reversible with protamine?
No
Does fondaparinux cause HIT?
No
-only Heparin and LMWH
What are the Hirudin analogs?
Bivalirudin
-not used much; second line for dual therapy w asparin
Route of entry for bivalirudin?
Must be given IV
-parenteral
MOA of argatroban
Prophylaxis and treatment of HIT
-monitored w PTT
Route of entry for argatroban
IV, short half life
MOA of Warfarin
Oral Inhibitor of vitamin K y-epoxide reductase
-decreases factors II, VII, IX, X and protein C/S
Clinical applications of Warfarin
Long term prophylaxis of thrombosis
-especially in those with a-fib and mechanical heart valves
How do you monitor warfarin?
PT/INR (eliminated by liver)
-goal=between 2-3
Is warfarin safe in pregnancy?
No, crosses the placenta and disrupts bone formation
What are the first two factors/proteins affected in warfarin?
Factor VII and Protein C
Why does warfarin cause skin necrosis?
Protein C has a shorter half-life, so it creates a hypercoagulable state
MOA of Rivaroxaban (and other xabans)
direct (oral) inhibitor of Factor Xa (activated factor X)
What are the advantages of Rivaroxaban over Heparin?
Rapid, Fixed dose, less bleeding, Fewer interactions, No need to monitor INR
Clinical applications of rivaroxaban?
Prevention of DVT after knee/hip replacement
Prevention of stroke in a-fib
What is important when taking rivaroxaban?
Must dose on time (short half life)
Contraindications to rivaroxaban?
Bleeds
Renal/hepatic impairment
Pregnancy
MOA of dabigatran
direct (oral) thrombin inhibitor
Clinical application of dabigatran
Prevention of stroke in those with non-valvular A-fib
If dabigatran safe in those with mechanical heart valves?
Nope, recently contrainidcated
Antidote to dabigatran toxicity?
Idarucizumab
Antidote to Xa inhibitors?
Andexanet alfa
What is important to remember when storing dabigatran?
Must keep it in the manufacturer bottle
-pills are unstable==keep dry and room temp
What are the thrombolytic drugs?
TPA drugs (end in -plase) -alteplase, reteplase, and tenecteplase
Streptokinase
Adverse effects of thrombolytics?
Bleeding and allergic rxns (streptokinase mainly)
How do you reverse the thrombolytic agents?
tranexamic acid and aminocaproic acid
What should you do with subsegmental PE?
Just watch and wait, unless at high risk for reoccurance then anti-coagulate
Can you send someone home with a PE
Yes if they are stable
When would systemic thrombolytic therapy for PE be done?
If SBP <90 and low risk for bleed or if pt deteriorates
-no if SBP >90
What is prefered for PE: Catheter or Fibrolytic therapy?
Fibrolytic therapy
