Haematology Flashcards
(34 cards)
PO Aspirin
MofA
Irreversibly inhibits COX –> so decreased thromboxane –> so decreased platelet aggregation
PO Aspirin
Uses
- Long term prevention of cardiovascular, cerebrovascular and peripheral vascular disease
- 2nd line for emboli/ thrombus in AF (when warfarin=CI)
- ACS treatment –> rapid inhibition of aggregation can prevent or limit arterial thrombosis
- Stroke treatment
PO Aspirin
Side effects
- GI irritation (NSAID) or haemorrhage if severe
- Tinnitus
- Overdose
PO Aspirin
Contraindications
- Children under 16yrs –> Reye’s syndrome
- 3rd trimester of pregnancy –> early ductus arteriosus closure
- Peptic ulceration
- Gout
PO Aspirin
Interactions
- Acts synergistically with other anti platelet agents (working together to produce enhanced result)
- Caution if used with anti-coagulants, e.g. if blood thinning disorder
- Lasts for lifetime of platelet (7-10 days) so discontinue 10 days before surgery
PO Clopidogrel
MofA
- Binds to ADP receptors (P2Y12) on platelets surface, so inhibits aggregation
PO Clopidogrel
Uses
- Long term prevention of cardiovascular, cerebrovascular and peripheral vascular disease
- 2nd line for emboli/ thrombus in AF (when warfarin=CI)
- ACS treatment –> rapid inhibition of aggregation can prevent or limit arterial thrombosis
- Prevents occlusion of coronary artery stents
PO Clopidogrel
Side effects
- Bleeding
- Thrombocytopenia
- GI upset
PO Clopidogrel
Contraindications
- Significant active bleeding
- Stop 7 days before elective surgery
PO Clopidogrel
Interactions
- Effects reduced by cytochrome p450 inhibitors (omeprazole, ciprofloxacin, erthryomycin, SSRI’s) since it is a prodrug.
PO Dipyridamole
MofA
- Increases cAMP to inhibit platelet aggregation
- Prolongs the effect of adenosine on blood vessels –> vasodilaton
PO Dipyridamole
Uses
- 1st line therapy following TIA
- 2nd line therapy for ischaemic stroke - when clopidogrel is CI
PO Dipyridamole
Side effects
- Headache
- Flushing
- Dizziness
- GI upset
(All above from vasodilation) - Bleeding
PO Dipyridamole
Contraindications
- Causes vasodilation and tachycardia, so use with caution in HF, IHD, aortic stenosis
PO Dipyridamole
Interactions
- Inhibits cellular uptake of adenosine so prolongs the effect on heart - reduce dose!
SC Heparin
Types
- Unfractioned
- Low molecular weight, e.g. Dalteparin
- Fondaparinux
SC Heparin
Uses
- Venous thromboembolism prophylaxis
- DVT and PE treatment
- ACS treatment
SC Heparin
Side effects
- Bleeding
SC Heparin
Contraindications
- Clotting disorders
- Uncontrolled hypertension
- Recent surgery
- Renal impairment - LMWH or fondaparinux may accumulate so use lower dose or unfractioned
SC Heparin
Interactions
- Combining anti-thrombotic drugs increases the risk of bleeding
- Special reasons for combined therapy - use of LMWH when initiating warfarin or in ACS
- Reversal = Protamine
Unfractioned Heparin
MofA
Activates antithrombin, which inactivates factor Xa and thrombin
LMW Heparin
MofA
Preferentially factor Xa inhibition
Fondaparinux
MofA
Factor Xa only
PO Warfarin
MofA
Inhibits production of Vitamin K-dependent coagulation factors (inhibits Vit-K epoxide reductase)
