3 Anticoag HH Flashcards
Complications of UFH use
Osteoperosis Heparin induced thrombocytopenia (HIT)
What are the two types of HIT
type 1 - platelet aggregation type 1 - platelet activating - a more rapid drop in platelet count, paradoxically causes THROMBOSIS. Seen 5-7days after initiation.
Action of coumarins?
Vit k epoxide reductase inhibitor - LEARN THE CYCLE
What is vit K used for?
gamma-carboxylation of Gla residues essential to activate clotting factors.
This converts vit K into vit K epoxide (and this is transformed back using vit K epoxide reductase)
How are platelets activated?
when unactivated there is an asymmerical distribution of phospholipids in hte membrane, this scrambles when activated. Becomes anionic allowing Ca binding
PT time tests the extrinsic or intrinsic pathway
exctrinsic
S/e warfarin
BLEED alopecia skin rash skin necrosis teratogenic agranulacytosis
Why do we give vit K as well as clotting factors in high INR?
short half life of clotting factors
Name the NOACs
rivaroxiban
apixiban
dabigatran
Mechanism of action of dabigatran
anti-IIa inhibitor
Mechanism of action of riv and apixaban
anti-Xa inihibitor
Warfarin: why is time in therapeutic range important?
under 50% of the time in therapeutic range actually shows worse survival than no warfarin
Look at the diagram of where anticoagulants work!
ssdfsdfjsdlkfjsldfj
Major advantages of NOACs? 4
Reproducible PK
No monitoring
Rapid onset
Oral
All NOACs are licensed for… (4)
VTW prophylaxis in hip/knee surgery
SPAF
treatment and secondary prevention of VTE
Disadvantages of NOACs
- Cost
- Extra care in some circumstances (see other card)
- unlicensed in preg and kids
- not reversible
- difficulty measuring effect
- drug interactions still possible
Care using NOACs with (4)
peri-op
epidural anesthesia
renal impairmen
wight 12kg
Reversal agents for NOACs are being investigated such as
MAB fragments and modified antifXa vairent
Which NOAC has OD dosing
Rivarox
NOAC to choose in high risk of stroke/bleed/renal impairment
Riv or Apix
NOAC to choose in previous MI or ACS
Riv
NOAC to choose for high GI bleed risk
Apix
NOAC to choose for high tisk of ischemic stroke
Dabigatran
Choice of anticoagulant:
Cr
Warfarin
Choice of anticoagulant:
Cr 15-30
riv 15mg od
or
apix 2.5mg bd
Choice of anticoagulant:
extremes of weight
Warfarin
Choice of anticoagulant:
children
Warfarin
Choice of anticoagulant:
heart valve prosthesis
Warfarin
Choice of anticoagulant:
cancer associated thromosis
LMWH
Choice of anticoagulant:
high GI bleed risk
warfarin or apixiban
Choice of anticoagulant: previous MI
warfarin or riv (maybe apix)
Thrombolytic agents
- Streptokinase (Kabikinase®, Streptase®)
- rt-PA, Alteplase (Actilyse®)
- Reteplase (Rapilysin®)
- Tenecteplase (Metalyse®)
Contraindications to fibriolysis in acute MI
Recent haemorrhage Trauma Surgery Coagulation defects Peptic ulceration Severe hypertension Acute pulmonary disease esp cavitation Acute pancreatitis Severe liver disease Previous allergic reaction
You can put a creepy spider device itno your …. to prevent PE
vena cava
There is evidence suggesting ….. and … should be used in combo for PE/DVT
anticoagulants and thrombolytics
Pharmacists role in anticoagulation
- Patient decision re-anticoagulation of choice?
- VTE risk assessment / management
- Initiation and dosing of anticoagulant drugs
- Monitoring and managing results
- Drug interactions
- Counselling patients
Non-pharmacological ways of avoiding VTE?
mobility and hydration
stockings
foot pumps
APTT measure intrinsic or extrinsic clotting time?
Intrinsic
APTT is normall
27-35 sec
don’t confuse APTT ratio with INR. APTT raio is APTT/control
LMHW doses are ….. adusted
UFH doses are …. adjusted
LMWH - weight
UFH - APTT
Name some LMWH
Dalteparine
Enoxaparin
Tinzaparin
How do you reverse heparin?
Protamine (it’s uncommonly needed) - more effective on UFH that LMW
