3-3, Drug Treatment Of Angina

Front 1

what is angina pectoris

Back 1

• chest pain due to myocardial ischaemia

Front 2

the pain which is associated with angina pectoris is due to what happening

Back 2

a build up of metabolites in the interstitial space:

-adenosine (from broken down ATP)

-CO2

-lactate

-K+ ions

these metabolites then activate sensory nerves

Front 3

what causes myocardial ischemia

Back 3

increased myocardial O2 demand which is not met

Front 4

what are the 3 types of angina

Back 4

stable angina

unstable angina

variant angina

Front 5

what is the most common and what is the least common form of angina

Back 5

stable agnina --> most common

variant angina --> least common

Front 6

are attacks predictable or non predictable in stable, unstable and variant angina

Back 6

stable --> predictable

unstable --> non-predictable

variant --> unpredictable

....makes sense doesn't it

Front 7

what causes stable angina

Back 7

myocardial O2 demand not being met

Front 8

what triggers stable angina

Back 8

exercise or stress

Front 9

is atherosclerosis present in stable angina

Back 9

yeaaaaaaaaaaaah

Front 10

how would you treat angina

Back 10

cholesterol lowering drugs (statins)

Front 11

what causes unstable angina

Back 11

coronary artery occlusion due to platelet adhesion to ruptured atherosclerotic plaque

Front 12

how would you treat unstable angina

Back 12

anti-platelet drugs

Front 13

what causes variant angina

Back 13

coronary artery occlusion by vasospasm

vasospasm causes intense vasoconstriction of coronary artery

Front 14

in what forms of angina is dilation helpful

Back 14

variant angina

because it can relax the vasospasm

Front 15

why is dilation of the coronary arteries dangerous in stable and unstable angina

Back 15

because it may cause coronary steal

this is where dilatation can occur, this sends more blood to already well perfused areas, but where dilatation cannot occur, less blood is delivered because of the fall in input pressure

Front 16

a decrease in what is helpful in all forms of angina

Back 16

a decreased myocardial Oxygen demand

Front 17

what 2 forms of drugs exist to reduce myocardial oxygen demand

Back 17

1) drugs acting directly on the heart:

2) drugs that cause vasodilation

Front 18

what are the drugs which act directly on the heart to redcue myocardial oxygen demand

Back 18

b1-adrenoceptor blockers – competitive reversible antagonists of adrenaline and noradrenaline at cardiac b1- adrenoceptor

decrease heart rate and force

decrease myocardial work

decrease myocardial O2 demand

Front 19

give 2 examples of adrenoceptors

Back 19

propano......lol (Beta 1&2)

atenolol (Beta 1 selective)

Front 20

what are the adverse affects of beta-adrenoceptor blockers in agnina

Back 20

(a) Exacerbate asthma (block of b2- adrenoceptors in bronchi - avoid by use of alternative drug class)

(b) Intolerance to exercise

(c) Hypoglycaemia

(d) Blockade of b-adrenoceptors may uncover a1- mediated constriction in coronaries

Front 21

adenosine and lactate are powerful vasoconstrictors, how do they aid/not aid the situations in different forms of angina

Back 21

in stable and unstable angina they are bad because they act as coronary vasodilators

in variant they can self resolve the angina due to their vasodilator function

Front 22

which drug was recently introduced to treat all forms of angina

Back 22

ivabradine

Front 23

how does ivabradine work

Back 23

Blocks If (Na+) current that contributes to SA node

depolarisation towards threshold

Decreases heart rate but not force

decreases myocardial O2 demand

Front 24

what 3 things to drugs which cause vasodilation to achieve lowered myocardial oxygen demand do which

Back 24

-dilation of arteries

-dilation of veins

-venous dilation

Front 25

in vasodilator drugs what happens during the dilation of the arteries

Back 25

decreased after-load (force against which left ventricle contracts)

decreased myocardial work
decreased myocardial O2 demand

Front 26

in vasodilator drugs what happens during the dilation of the veins

Back 26

decreased pre-load

(the diastolic pressure that distends the relaxed left ventricle)

Front 27

in vasodilator drugs what happens during the venous dilation

Back 27

decreased venous return

decreased pre-load
decreased stretch of ventricle

decreased strength of contraction

decreased myocardial work
decreased myocardial O2 demand

Front 28

what type of drugs are the most commonly used anti anginals

Back 28

nitrovasodilators

Front 29

give 2 different examples of nitrovasodilators

Back 29

• glyceryl trinitrate (nitroglycerine, 10% in inert lactose base) • taken as sub-lingual tablet or spray
• not orally active (destroyed by first-pass metabolism)

• amyl nitrite (volatile liquid)

• vials opened and inhaled

• not now used clinically but has become drug of abuse (poppers)

Both drugs rapid in onset, but action short-lived

Uses:

• prophylaxis in stable angina (i.e. taken immediately before exercise)

• rapid relief of ongoing anginal attack (all forms)

Front 30

give 2 other nitrovasodilators

Back 30

isosorbide dinitrate

isosorbide mononitrate

• taken orally
• slower in onset and more prolonged in duration than GTN • used for sustained prophylaxis in all forms of angina

Front 31

how do nitrovasodilators work

Back 31

• nitrovasodilators all lipophilic - readily enter smooth muscle cells and are reduced to nitric oxide (NO)

• nitrovasodilators termed “NO donors”
• mimic action of endothelium-derived NO