Cardiovascular therapeutics workshop Flashcards
How does dabigatran act
Direct oral anticoagulant
-Direct thrombin inhibitor.
Because thrombin (serine protease) enables the conversion of fibrinogen into fibrin during the coagulation cascade, its inhibition prevents the development of a thrombus
when are results of a trial significant
If the P value is less than 0.05
How does aspirin act
Irreversible COX inhibitor. Platelets have no nuclei so can’t produce thromboxane so inhibits platelet aggregation. Using low dose aspirin favours prostacyclin which prevents platelet aggregation
What does alteplase do
Dissolves clots and activates plasminogen to be turned into plasmin which digests the fibrin of the clot. It also inhibits coagulation factors
What must you check before prescribing a fibrinolytic
MUst make sure that the stroke is formed from a clot and not a haemorrhage (bleed)
When shouldn’t alteplase be prescribed
When the patient has bleeding conditions such as stomach ulcers
When can’t you have aspirin
Peptic ulceration and when there is aspirin sensitivity
What drugs may be used as an alternative to low dose aspirin
CLopidogrel
what is the mechanism of action of warfarin
Inhibits vitamin K reductase which is needed for vitamin K to act as a cofactor in the production of active coagulation factors
What does clarithromycin do when used with warfarin
Increases the anticoagulant effect of warfarin so the INR rises and there is less production of coagulation factors
What does clarithromycin do
Inhibits cytochrome P450 (therefore inhibits the metabolism of warfarin)
What does the FBC pf a patient with iron deficiency anaemia look like
Reduced haemoglobin
MIcrocytosis (reduced MCV as the cells are smaller)
Reduction in iron stores
What does a high haemoglobin count show and why Is this bad
Polycythaemia- Body may be making too many red blood cells which would lead to the blood being thicker than usual and so this would increase the risk of stroke and heart attacks and clots
What does a FBC with low haemoglobin levels and low iron stores show
Anaemia
What does the blood count of a person with normocytic anaemia show
- Low haemoglobin levels
- High white blood cell count
- Low platelet level
- Normal iron stores
What is normocytic anaemia
have normal-sized red blood cells, but you have a low number of them
What does the FBC of a person with macrocytic anaemia look like
- Low haemoglobin
- Higher MCV
- Normal iron stores
What is macrocytic anaemia
Causes abnormally large red blood cells
What is macrocytic anaemia caused by
Deficiency in vitamin B12 or folate
What causes iron deficiency anaemia
Chronic blood loss
What can cause polycythaemia
- Dehydration
- Red cell defect where too many red cells are produced
- Chronic hypoxia (not enough oxygen)
What causes normocytic anaemia
Chronic kidney disease?
pregnancy?
What is megaloblastic anaemia
When bone marrow produces abnormally large red blood cells
How to treat polycythaemia
- Radioactive phosphorous to suppress bone marrow
- Bone marrow transplant and/or chemotherapy
How to treat macrocytic anaemia
Vitamin B12 and/or folic acid supplements
What does a relative risk of 1 man
No change in risk
What does a relative risk less than 1 mean
Decrease in risk
What does a relative risk more than 1 mean
Increase in risk
