Angina control drugs and drugs for treatment following an MI

Question 1

What is the function of Nitroc oxide (NO)

Answer 1

It is an endothelium-derived relaxing factor
It causes:
Venous vasodilation /pre-­‐load reduction
Arterial dilation /after-­‐load reduction
Coronary artery vasodilation
Prevention of coronary vasoconstriction
Enhancement of coronary collateral flow
Antiplatelet and antithrombotic effects

Question 2

What is the mechanism of action of nitrates

Answer 2

Increase the production of NO from the endothelium
They are metabolized to increase NO
1) NO stimulates guanylate cyclase
2) Gaunylate cyclase synthesizes cGMP
3) cGMP activates cCGMP –dependent protein kinase
4) cGMPdK activates myosin light chain phosphate(s) (MLCP)
5) Myosin light chains in the smooth muscle cells are dephosphorylated.
6) The contractile state of the smooth muscles
depends on phosphorylation of the myosin light chains (calmodulin-­‐dependent kinase phosphorylates)

Question 3

Give examples of nitrates used to treat angina

Answer 3

Nitroglycerin (fast acting)
Isosorbide mononitrate
Isosorbide dinitrate 
Transdermal patches (long acting)
Alkyl Nitrates (poppers)

Question 4

What are the side effects of the nitrates

Answer 4

Headach 
Flushing 
Palpatations 
Tolerance 
Major interaction with viagra leading to hypotensive crisis

Question 5

Give examples of beta-blockers used to treat angina

Answer 5

Propanalol
Atenolol
Carvedilol

Question 6

What is the function of beta-blockers

Answer 6

They reduce myocardial oxygen demand

Question 7

What is the mechanism of action of propanolol

Answer 7

non-selective Beta1 and Beta2 adrenoreceptor blocker

Question 8

what is the mechanism of action of atenolol

Answer 8

more beta-1 selective blocker

Question 9

what is the mechanism of action of Carvedilol

Answer 9

Beta blocker and also blocks alpha-adrenoreceptors imprvign coronary perfusion

Question 10

When are beta-blockers used

Answer 10

first-­‐line therapy in the treatment of chronic
stable angina (esp. effort-­‐induced angina)

Question 11

What are the side effects of the beta-blockers

Answer 11

constipation
indigestion
hypotension 
sleep disturbances 
hallucinations (rare)
reduce aqueous humor secretion (good for treating glaucoma)
skin reactions e.g. hives, psoriasis

Question 12

Give examples of Ca2+ channel blockers used in the treatment of angina

Answer 12

Dihyropyridines e.g. Nifedipine

Phenylalkylamines e.g. Verapamil

Benzothiazepine e.g. Diltiazem

(also non-­‐selective VDCC blockers e.g. Fluspiriline)

Question 13

What is the mechanism of action of the Ca2+ channel blockers

Answer 13

Ca2+ entry to Smooth Muscle depends on
activity of voltage dependent Ca2+ channels
(mainly L-­‐type Voltage Dependant Calcium Channels)
They are L-­‐type VDCC antagonists

Question 14

What are the side effects of the Ca2+ channel blockers

Answer 14

Peripheral vasodilation: dizziness, headachs, erythema
constipation
heart rate changes
Gingival overgrowth

Question 15

What are Phenylalkylamines e.g. Verapamil

selective for

Answer 15

myocardium hence they have minimal peripheral vasodilatory effects (compared with Dihyropyridines)

Question 16

What are Benzothiazepine e.g. Diltiazem good for

Answer 16

Having both cardiac depressant and
vasodilator actions, benzothiazepines are
able to reduce arterial pressure without producing as much reflex cardiac stimulation
caused by dihydropyridines.

Question 17

Give an example of an antiplatelet drug used to treat angina

Answer 17

Clopidogrel

Question 18

What is the mechanism of Clopidogrel

Answer 18

It is a pro-drug which blocks the ADP receptor on the platelet membrane preventing platelet aggregation and clot formation

Question 19

What are the side effects of Clopidogrel

Answer 19

Haemorrhage
Severe neutropenia
Thrombotic thrombocytopenic purpura (paradoxical)

Question 20

What is the mechanism of action of asprin

Answer 20

It is synthesized to salicylate
It inhibits thromboxane A2 production by inhibiting COX
It thus has an antiplatelet effect

Question 21

What is asprin used for at low doses

Answer 21

Help prevent heart attacks (may be given immediatly after heart attack to reduce the risk of a second heart attack)
Help prevent strokes
Help prevent bood clots

Question 22

What are the side effects of asprin

Answer 22

GI ulcers/ bleeding

Tinnitus

Question 23

What is used to minimize cardiac dysfunction following ischemia

Answer 23

Ranolazine

Question 24

what is the mechanism of action of Ranolazine

Answer 24

It blocks late Na+ entry reducing cardiac dysfunction by:

Increasing the QT interval

Question 25

What does ranolazine decrease

Answer 25

It decreases angina episodes in individuals with coronary artery disease on maximal doses of amlodipine and exercise tolerance in those taking atenolol, amlodipine or diltiazem

Question 26

What are the side effects of Ranolazine

Answer 26

Worsen electrical dysfunction in long-OT syndrome which could lead to sudden cardiac death