ACS and Heart Failure Flashcards
MOA of Aspirin
NB: anti platelet effect occurs at low doses and lasts for lifetime of platelet
Irreversibly inhibits cox reducing platelet aggregation
Give 3 SEs of Aspirin
- GI irritation, ulcer, haemorrhage
- bronchospasm
- tinnitus
2 contraindications of aspirin?
- children <16
- aspirin sensitivity
- 3rd trimester pregnancy
What conditions should you have a caution about giving aspirin in?
- peptic ulcer disease
- gout
In ACS prescribe a loading dose of aspirin ___mg, followed by a regular daily dose of ___mg
300mg
75mg
Warfarin MOA
-inhibits vitamin K epoxide reductase (responsible for synthesis of clotting factors)
2 indications for the use of statins and 3 examples of names of statins
- primary prevention of CV events (MI/stroke) w QRISK >10% 40yrs+
- secondary prevention of CV events (+lifestyle changes, to prevent events in pts with established CV disease)
- primary hyperlipidaemia treatment
- e.g. rosuvastatin, parvastatin, simvastatin, atorvastatin
MOA of statins
- inhibits HMG Co-A reductase decreasing serum cholesterol levels
- also increases clearance of LDL cholesterol from blood
- indirectly reduces triglyceride levels, and increase HDL
3 statin SEs?
- headache
- GI disturbance
- muscle aches, myopathy
- rhabdomyalisis (rare)
- elevated liver enzymes (e.g ALT)
Statin cautions
- hepatic impairment
- renal impairment - reduce dose
- avoid pregnancy/breastfeeding
Statins are metabolised by
Cytochrome p450 enzymes (so inhibitors of this enzyme reduce the effect of statins)
Give 1 SEs of warfarin use?
- bleeding
- increased risk w trauma and peptic ulcers
- OD can —> spontaneous bleeding
2 Warfarin contraindications:
- pt at immediate risk of haemorrhage (trauma, surgery)
- liver disease
- 1st trimester pregnancy
What type of medications increase warfarin metabolism therefore lower the therapeutic effect and leave pt at risk of clots?
CYP inducers
3 SEs of heparin
- haemorrhage
- bruising at injection site
- hyperkalaemia (effects on adrenal aldosterone secretion)
- heparin induced thrombocytopenia (HIT) - rare immune reaction, low platelet count and thrombosis (!) - more with UFH
Give 2 indications for Heparin (e.g. enoxaparin, dalteparin, UFH, fondaparinux)
- VTE prophylaxis for in-pts, or initial VTE rx until oral anticoagulation is established
- ACS: LMWH/fondaparinux used with antiplatelets to reduce clot progression/maintain revascularisation
Heparin MOA
- antithrombin inactivates clotting factors IIa and Xa
- heparin enhances this anticoagulant effect of the antithrombin
We know that heparins act by (antithrombin inactivates clotting factors IIa and Xa), heparin enhances this anticoagulant effect of the antithrombin, how does the size of the heparin relate to the specificity UFH vs LMWH?
- UFH: large and small molecules, these promote inactivation of both factor IIa and Xa
- LMWH: smaller molecules, is more specific for factor Xa
NB: Fondaparinux is a synthetic polysaccharide that mimics the sequence of the binding site of heparin to AT and is very specific for factor Xa
When should you exercise caution in prescribing heparin?
- increased bleeding risk (clotting disorder, severe uncontrolled HT, recent trauma/surgery)
- withhold before and after an invasive procedure
- renal impairment
What type of heparin should be used in renal impairment and why? /reduce dose
- UFH should be used
- as LMWH and fondapariux will accumulate so requires a much lower dose/don’t use
In major bleeding, what 2 agents can reverse UFH action but is less effective for LMWH (and no effect on fondaparinux)
Protamine
Andexanet
A typical VTE prophylaxis dose is dalteparin ___ UNITS daily, mode of administration is ___, in renal impairment can give ___ ““UNITS “” mode 12-hrly
- 5000 UNITS
- Subcutaneous (into abdo wall not arm as can –> uncomfortable/disabling bruising)
- Unfractionated Heparin 5000 UNITS
LMWH and fondaparinux effect is predictable enough to not need monitoring, but UFH when used therepeutically must have the dose titrated against the activated ___ ____ ratio (APTR) with a usual target of ___. FBC, clotting and renal profiles must be checked pre-rx, what 2 blood tests must be monitored in case of HIT?
- Activated partial Thromboplastin Ratio (target 1.5-2.5)
- Platelet count and serum K+
3 indications for the use of ACEi
- HT
- Chronic HF
- Ischaemic Heart Disease
- Diabetic Nephropathy and CKD w proteinuria