Haematology Drugs and Tests Flashcards
What is Prothrombin Time Measuring/ PT?
Extrinsic Pathway
Factors:
VII, X, V, II and fibrogen
What does APTT measure?
Intrinsic Pathway
XII, IX, XI, X, VIII, II and fibrinogen
What does the clotting time measure?
how long it takes for fibrinogen to turn to fibrin.
the tests literally add thrombin. therefore it is not relying on any of the factors other than fibrinogen.
indication of:
- decreased fibrinogen
- inhibitor
How does Warfarin work?
Blocks Vitamin K Oxide Reductase
No Reduced Vit K made.
No Carboxy-glutamic Acid Residues made on factors. therefore Ca2+ can’t bind and activate.
What factors for Warfarin disabled?
II, VII, IX, X
Protein C
Protein S
Name a factor IIa inhibitor:
Dabigatran
Name three factor Xa inhibitors:
Rivaoxaban
Apixaban
Edoxaban
Name a reversal drug of dabigatran:
Idarucizumab
Name two kinase fibrinolysis:
Streptokinase
Urokinase
Name three tissue plasminogen activators:
Atelplase
Tenecteplase
Reteplase
Name two ADP inhibitors:
Clopidogrel
Ticlopidine
By blocking ADP receptors on platelets, what is achieved?
decreased expression of:
Glycoproteins IIb/ IIIa
reduced fibrinogen binding
Name two GP IIb/ IIIa antagonists:
Abciximab
Tirofiban
Name phosphodiesterase III inhibitor and how does it work?
Dipyridamole
Blocks cAMP levels from being reduced. thus maintaining them.
which deactivates platelets.
What are the common pathway factors, and what would the result be on the APPT and PT?
1,2,5, and 10
both would be increased as both involve them
Can heparin be used in pregnancy?
Yes - they don’t cross the placenta
When do you use heparin?
Acute short term situation
- pre opp
- DVT
usually low molecular heparin used
What is the half life of Warfarin?
36 hours
What’s the INR wanted in warfarin and what does it mean?
2-3 INR.
Means 2-3 x longer time to clot
When is warfarin used?
AF
Acute DVT or Pulmonary Embolism (following heparin used)
Prosthetic heart valve.
How quickly do the DOACs work?
Immediately
What DOACs can’t be used in renal disease?
Dabigatran
Whats a draw back of DOACs?
No reversible treatment - so if bleeding nothing that ca be done
How does tPA differ from kinases?
They only activate plasminogen at the site of the clot
Who gets tPA and when?
Must be given within 4.5hours
Ischemic stroke
M.I - when PCI is not indicated
Massive pulmonary embolism that is immediate life threatening
In DIC what blood results would you expect to see?
Pre-longed clotting times - used up coagulation.
Increased D - Dimers
- break down of the clots that inappropriately formed
sliced RBCs
Treatment of DIC
Coagulation factors
Fresh Frozen plasma
Treat underlying conditions
What do you do if the INR of someone is on warfarin is too high?
Vitamin K
- takes about 6 hours to take effect
or
Immediate action - can give coagulation factors
- Beriplex
List some causes of bleeding disorders in alcoholic:
Liver failure - lack of coagulation factor production
Poor diet - Lack of Vitamin K intake
Poor clearance of activated coagulation factors
If someone has Haemophilia A or B, what test will identify it?
These are factors 8 and 9 that are affected.
thus APPT will be affected.
What is the new name for the intrinsic pathway?
Propagation
What is the new name for the extrinsic pathway?
Initiation pathway
