Class 8 Deck 1 Flashcards
Heparin is an ________, ___________ glycosoaminoglycan found in the secretory granules of __________.
- Anionic (charged)
- Sulfated
- Mast Cells
How does heparin work?
- accelerate rate which ATIII neutralizes thrombin (IIa) and factor Xa
- Prevents fibrinogen from converting to fibrin
When is heparin used?
- Phophylaxis treatment of Embolisms
- DIC
- Anticoag during cardiac surgery
- Management of angina, MI, PCI
- Pregnancy complications
Heparin can only work on what type of factors?
-Unbound (not attached to platelet)
Heparin is cleared by what?
-Reticuloendothelial system
Does heparin cross the placenta? Warfarin?
- Heparin does not cross placenta
- Warfarin does cross the placenta
What can cause heparin resistance?
- Increased factor VIII
- Accelerated clearance w/ massive PE
- Inherited ATIII deficiency
- Acquired ATIII deficiency
What causes acquired ATIII deficiency? and how to treat?
- Cirrhosis, Nephrotic syndrome, DIC
- FFP or ATIII concentrate
What are some problems associated with heparin toxicity?
- Bleeding
- Thrombocytopenia (HIT)
- Abnormal LFTs
- Osteoperosis / vertebral fractures
What is protamine?
- Low molecular weight, cationic, strongly basic protein
- from Salmon sperm
- Heparin antagonist
Protamine has what effect on LMWHs?
-Not as effective, only 65% neutralization
What are the doses of protamine?
- 1-1.5mg per 100 units of heparin
- 0.5-0.75 after 30-60 minutes
- 0.25-0.375 after 2 hours
What are the adverse effects of protamine?
- Histamine hypotension
- Brady
- Pulmonary HTN
- Flushing
- Dyspnea
What are the hypersenitivity reactions of protamine?
- Uticaria
- Angioedema
- Pulmonary HTN
- Anaphylactoid/Anaphylaxis
What groups of people are at risk for hypersensitivity to proatmine?
- Fish allergy
- Previous protamine reversal
- Protamine containing insulin (NPH)
- Previous vasectomy
How do you pretreat for protamine hypersensitivity?
- Corticosteroids
- Antihistamine
What is heparin rebound?
- Re-anitcoagulate after protamine reversal
- Usually 8-9 hours (reported 30min to 18hrs post CPB)
What can happen with protamine OD?
- Bleeding
- Has anticoags and antiplatelets when given alone or in excess of heparin
Name 3 LMWH
- Dalteparin
- Enoxaparin
- Tinzaparin
How do LMWH work?
-Inhibition of factor Xa by antithrombin
What are the advantages of LMWH?
- Fixed dose sub Q
- Not dose monitoring or adjustments
What are LMWH uses
- Post op DVT/Embolisms
- Angina, MI, AFib
Can dosages of LMWH and Heparin be used interchangeably?
No
What are the adverese effects of LMWH?
- Thrombocytopenia
- Do not use with HIT
- Decrease dose in renal patients
What does Fondaparinux (Arixtra®) do?
- Synthetic inhibitor of factor Xa
- ATIII mediated
- No effect on IIa or platelets
Advantages of Fondaparinux (Arixtra®)?
- Fixed dose / Once daily
- No monitoring or dose adjustments
- No HIT (stop use if platelets fall below 100,000)
When is Fondaparinux (Arixtra®) used?
-Prevention / treatment of DVT/Embolism
What 2 anticoags can cause spinal or epidual hematomas?
- LMWH
- Fondaparinux (Arixtra®)
What kind of drug is Danaproid Sodium (Orgaran ®)?
Heparinoid
- anti-factor Xa
- Contains no Heparin
What is Argatroban (formerly Acova®) and what does it do?
- Direct / reversible thrombin inhibitor
- Works on bound and unbound thrombin
Argatroban (formerly Acova®) is used for what?
-Thrombus in patients w/ HIT or HITTS (those that can’t use heparin)
Name 2 Hirundin Analogs (leech saliva)
Bivalirudin (Angiomax ®)
Lepirudin (Refludin®)
How does Lepirudin (Refludin®) work?
- direct thrombin inhibitor
- Binds irreversibly to bound and unbound thrombin (IIa)
When is Lepirudin (Refludin®) used and how is it excreted?
- thrombosis associated with HIT
- Kidneys
How does Warfarin work?
- indirect anticoagulant
- Alters factors II, VII, IX, and X by interfering with vitamin K.
What is the treatment for warfarin bleeding?
- Vitamin K (Takes 24hrs)
- FFP (immediate)
Warfarin is what kind of pregnancy drug?
Category X
Warfarin interacts with what other drugs?
- ABX
- Acetaminophen
- Antiepiletics
- Blood thinners
- NSADIS
- Supplements
Name 3 Novel Oral Anticoags
Dabigatran (Pradaxa®): Oral direct thrombin inhibitor
Apixaban (Eliquis®): Oral direct Factor Xa inhibitor
Rivaroxaban (Xarelto®): Oral factor Xa inhibitor
Dabigatran (Pradaxa®) is eliminated how?
- 80% by kidneys
- Dose adjustments needed for CKD
Dabigatran (Pradaxa®) should be held for how long prior to surgery?
- CrCl >50 1-2 days
- CrCl < 50 3-5 days
ApiXaban (Eliquis®) is used when?
- Reduce stroke and embolization in patients w/ non-valvular AFib
- DVT after total hip
RivaroXaban (Xarelto®) is used when?
- Reduce stroke and embolization in patients w/ non-valvular AFib
- DVT after total hip / Knee
Should be used with caution in what type of patients?
-Renal failure
Apixaban should be used with caution in what type of patients?
-Liver failure
Novel Oral Antigcoags should not be used with what other drugs?
- Strong inhibitors/inducers of CYP3A4 or P-Glycoproteins
- NSAIDS
- Anitplatlet
