M103 T3 L14 Flashcards
What are the two ways in which drugs are designed to treat hypercholesterolaemia?
to inhibit cholesterol uptake from GI tract
to reduce cholesterol production in liver
Where is cholesterol produced?
85% - liver
15% - food eaten
What are two examples of statins? (SIMulATOR)
SIMvastatin
ATORvastatin
What is the role of HMG CoA reductase?
used to synthesise CLSR in the liver
What is the effect of inhibiting HMG CoA reductase?
reduces the amount of cholesterol produced by the liver
What happens when the amount of cholesterol produced by the liver is reduced?
genes that produce the LDL receptor are activated
LDL particles bind to the LDL receptor on liver cells
LDL particles become internalised
Where are the LDL receptors expressed?
on the surfaces of cells that require CLSR - this is usually liver cells
When do cholesterol particles do the most harm?
when they are outside of cells in the bloodstream
When do cholesterol particles do the least harm?
when they are inside of cells
What are two examples of antiplatelet agents?
AsPiriN
cloPidogrEL
ANtiPlatELet
What is an example of an ACE Inhibitor?
rAmIpril
What are three examples of an ARB? (LOve VAlour CANDor)
LOS-artan
VALS-artan
CANDES-artan
What is the end goal of an ARB?
to decrease the workload of the heart
What three conditions does stable angina digress into?
unstable angina
NSTEMI, STEMI
How is stable angina treated?
(Bonk & CoNk)
β-blockers
CCBs
Nitrates
How is unstable angina treated?
stable angina treatment (Bonk & CoNk) + ANTIPLATELETS
Why are antiplatelets added when treating unstable angina?
bc the atherosclerotic plaques are more likely to rupture and form a thrombus in unstable angina
What are the antiplatelet drugs used to treat unstable angina?
aspirin
clopidogrel
G What are two alternatives to clopidogrel?
prasugrel
ticagrelor
What are the two phases platelets have to go through before agglutination can occur?
activation
aggregation
When do platelets begin to be activated?
when endothelial cells are damaged
when the plaque ruptures
Why are platelets activated when the plaque ruptures?
lots of substances under the endothelium drive their activation, e.g. ADP, collagen & COX
Which two substances are key to platelet activation?
ADP & TXA2
By what process does TXA2 further activate platelets?
positive feedback
How does aspirin work as an AntiplAtelet Agent?
it inhibits COX irreversibly
it prevents the production of TXA2
reduces platelet activation
What are three examples of ATP receptor antagonists?
(PCT)
clopidogrel
prasugrel & ticagrelor alternatives
What is the effect of ATP receptor antagonists?
they prevent platelet aggregation
Why is the prevention of platelet aggregation beneficial?
in a patient with unstable angina
How does platelet aggregation cause pain?
platelets sticking together block coronary arteries
cause the pain that’s associated with an ischaemic event
What is special about clopidogrel?
it was the first P2 Y12 receptor antagonist to be developed
it’s a prodrug
What activates clopidogrel?
CYP2C19
How does prasugrel work?
it undergoes hydrolysis by an esterase to form an intermediate compound, then an active compound
What is a disadvantage of both prasugrel and clopidogrel?
they both are irreversible
What is a consequence of the irreversibility of prasugrel and clopidogrel?
if bleeding occurs, it’s very difficult to reverse the effects of the drugs quickly
Which P2 Y12 receptor antagonist is reversible?
ticagrelor
What is the pathway of ticagrelor?
it’s absorbed from the gut
some gets metabolised
some is absorbed as the active ingredient
binds to the ATP receptor
What symptoms are used to diagnose a heart attack?
pain that does not go away with rest
sweating
tachycardia
cold clammy skin
What do the symptoms of a heart attack indicate about the NS?
that there is a problem with the sympathetic NS
What causes the symptoms of a heart attack?
heart has becomed damaged
cardiac output is impaired
bp drops and is detected by baroreceptors
they send signals to the medulla oblongata
activates the sympathetic system
What is the treatment for a heart attack?
pain relief, oxygen
aspirin / GTN
fibrinolytics