Anticoagulation Flashcards
1
Q
Injectable anticoagulants
A
- Unfactioned Heparin
- or LMWHs (enoxaparin, tinzaparin)
2
Q
Heparin MOA
A
- Activates antithrombin III to inhibit serine proteases in forming X, IX, Xi and Thrombin
- Immediate action
- Used whilst warfarin takes effect
3
Q
Monitoring unfractioned heparin
A
APTT
- Intrinsic pathway
- Altered by 1 (fibrinogen), 2(prothrombin), 5, 7, 8, 9, 10, 11
- Platelets: >5 heparing may cause thrombocytopenia
- LMWH do not require monitoring
4
Q
DVT/PE RFs
A
- Surgery
- Pregnancy
- Oestrogens
- Malignancy
- MI/HF
- Obesity
- >40
- Coagulation disorders
- Immobility
- Past VTE
- Trauma
5
Q
Warfarin MOA
A
Oral anticoagulant, prevents unwanted thrombosis in
Replaced heart vlaves, AF, PE , DVT
- Vit K antagonist
- Required for X, IX, VII, I
- BLocks Vit K reductase
- Takes several days
6
Q
Monitoring warfarin
A
Prothrombin time
- Time for coagulation following addition of thromoplastin
- Prolonged by VII, X, V, II, I abnormalites
- Normals INRs around 1
7
Q
Target INR is 2.5 for most conditions, but 3.5 in mechanincal heart valves
A
8
Q
Patient considerations with Warfarin
A
- take at 6 pm
- Miss a dose? do not take two together, and inform doctors at next test
- Avoid pregnancy on Warfarin
- Alcohol may be consumed in moderation
- Avoid excessive green vegatbles + beetrot and liber
9
Q
Complications patients on warfarin should report
A
- Haemoptysis
- Blood in faeces or urine
- Nose bleeds >20-30 min
- Easy brusing
- Skin changes
- Diarrhoea/vomiting for 2+ days
10
Q
Warfarin and pregnancy
A
Pregnancy produces thrombophilic state in mothor preventing post partum haemmorhage.
- Warfarin is teratogenic
- Chondroplasia punctata
- Optic atrophy
- Mental retardation
- Avoid in trimester 1 and 3. Favour LMWHs
11
Q
New anticoagulants MOA
A
DAbigatran: Oral thombin inhibitor. Prevents TE
- Less bleeding than W
- Fewer interactions
- No monitorin
- Ewually as effective in AF
Rivaroxaban: Oral inhibitors of activated factor X
