MI Flashcards
Immediate treatment?
Includes morphine, oxygen, nitrates, aspirin, rest and reassurance.
Thrombolytic agents end in
-ase
E.g. of thrombolytic agents
Alteplase and reteplase
How are thrombolytic agents administered
Administered by IV within 12 hours of onset of chest pain
When are thrombolytic agents usually administered
Typically in ED and followed up by transfer to the cardiac care unit (CCU)
What needs to be avoided post-administration of thrombolytics?
Post-administration need to avoid IM and other invasive procedures during IV therapy
What do patients need to be monitored for after thrombolytics administration
Need to be monitored for hypotension and treated accordingly
When do you stop treatment with thrombolytics?
If severe bleeding occurs, stop infusion and treat
How do thrombolytics work?
Work by converting plasminogen to plasmin, which then catalyses or breaks down the fibrin clot. They help to dissolve the embolus but can cause bleeding and transient hypotension
Contraindications of thrombolytics
Contraindicated for use in active bleeding, recent major surgery (<1 month), trauma, risk of intracranial haemorrhage, history of stroke (haemorrhage) or ischaemic stroke within a year, intracranial neoplasm and intracranial aneurysm
What do anti platelets do
Inhibit platelet aggregation thus reducing the risk of clot formation on stent
What is aspirin and what does it do
Aspirin, low dose standard therapy, works by inhibiting platelet aggregation by irreversibly inhibiting cyclo-oxygenase
Aspirin is an
anti platelet
Clopidogrel is an
anti platelet
What does clopidogrel do
Clopidogrel binds to the platelet P2Y12 receptors and inhibits platelet aggregation
What are the side effects of anti platelets
All have side effects e.g. bleeding and thrombocytopenia
What do anticoagulants do
Provide symptom relief, prevent further clots, reduce morbidity and mortality.
Heparin is an
anticoagulant
What does heparin do
Forms a complex with antithrombin III, inactivates clotting factors IIa (thrombin) and Xa to prevent further clots (does not dissolve current clots)
Low-molecular-weight heparin (LMWH) and danaparoid have a
much greater effect on factor Xa than on thrombin
What is danaparoid
an anticoagulant that is a more selective inhibitor of factor Xa than LMWHs
Heparin is administered in
high doses for treatment and low doses for prevention
AEs of heparin
Bleeding, bruising and pain at injection site, hyperkalaemia, mild reversible thrombocytopenia (does not necessarily indicate increased risk for severe thrombocytopenia)
What do you monitor when using heparin
Monitor activated partial thromboplastin time (aPTT) aiming for levels around 1.5-2.5 times more than the normal measurement. Measure ~6 hours after a bolus dose and then adjust for IV infusion
LMWH are
Similar in size and have the same anticoagulant activity (affect only factor Xa). No need to monitor aPTT
AEs of LMWH
Haemorrhage, gut-bleeding, bruising and pain at injection site
Clinical considerations for heparin
o Standard heparin: monitor aPTT (normal 25-40 sec)
o LMWH: longer half-life, safer and no need to monitor aPTT
o Report signs of bleeding
What does warfarin do
Inhibits epoxide reductase thus depleting vitamin K from the liver and interfering with the hepatic synthesis of vitamin K-dependent clotting factors X, IX, VII and II (prevents a new thrombus forming)
Normal dosage of warfarin?
A loading dose of 5-10mg for 2 days is then adjusted according to the International Normalised Ratio (INR) test. The daily maintenance dose range is 1-10mg
What do warfarin interact with?
Warfarin interacts with herbal meds, excessive amounts of green leafy vegetables and numerous other drugs
AEs warfarin
bleeding, alopecia (rare), fever, rash and hepatic dysfunction
How is rivaroxiban given?
Orally
Who is rivaroxiban given to
Is overtaking warfarin in younger patients with atrial fibrillation, acute venous thromboembolism and prevention
What is the mode of action of rivaroxiban?
Mode of action: selective inhibition of Xa, blocking thrombin production and thrombus formation (no human data for pregnancy)
AEs of rivaroxiban
Bleeding, itch, peripheral oedema, muscle spasm
