Myocardial Ischaemia Drug

Question 1

Types of drugs used to treat angina and examples.

Answer 1

1) Nitrates: Glyceryl Trinitrate, Isosorbide dinitrate/ mononitrate, Nicorandil
2) Beta-blocker: bispropolol
3) Calcium Channel Blocker: Amlodipine, Nifedipine, Dilfiazem
4) Others: Ivabradine, Ranolazine

Question 2

How does beta blocker work as treatment for angina?

Answer 2

It is a negative inotropic decreases oxygen demand, decreases heart rate, and has antihypertensive property.

Question 3

How does nicorandil work?

Answer 3

As a K/ATP channel agonist for hyperpolarisation

Question 4

Why cannot use Verapamil for heart failure?

Answer 4

Cause it will cause heart block

Question 5

How does Ivabradine work?

Answer 5

It decreases HR and works via activation of “funny channel”, which hyperpolarised SA node causing inward Na current.

It also decreases cardiac pacemaker potential without affecting force of cardiac contraction.

Question 6

How does ranolazine work?

Answer 6

It causes inhibition of late sodium current,
decreases intracellular Ca2+,
decreases muscle tension and oxygen demand,
and decreases HR without affecting force of cardiac contraction.

Question 7

What is Fibrinolytic drug? And examples.

Answer 7

Drug that lyse the thrombi that block coronary arteries.

Examples: Streptokinase, rtPA (recombinant Tissue Plasminogen, Activator): alteplase, tenecteplase, reteplase.

Question 8

Give a drug that will bind to plasminogen and cleaved it to generate plasmin.

Answer 8

Streptokinase

Question 9

In what condition needs to prescribe fibrinolytic drug?

Answer 9

Given within 12 hours of acute STEMI for activation of plasminogen

Question 10

What is the routine management for MI?

Answer 10

PCI (percutaneous coronary intervention)

+ drug-eluting stent

+ drug coated (sirolimus/rapamycin , paclitaxel)

Question 11

How does sirolimus( rapamycin) work?

Answer 11

• Inhibit mTOR

- Decrease proliferative effect of cytokines (IL-2)

Question 12

How does paclitaxel work?

Answer 12

Arrest cell cycle G2 and M phases

Question 13

What can be done for secondary prevention of MI?

Answer 13

1) Dual antiplatelet therapy: Aspirin + Tricagrelor (more preferred due to reversible )/ Clopidogrel (irreversible action)
2) statin therapy
3) ACE inhibitor (aldosterone antagonist: spinolactone, epleronone)
4) Beta- blockers

Question 14

How does aspirin work for MI prevention?

Answer 14

• Decrease thromboxane synthesis

- Acetylates cox enzyme (irreversible inhibition)

Question 15

Which drug is preferred over clopidogrel? And why?

Answer 15

Ticagrelor.

It treats acute coronary syndrome.
It is not a prodrug and thus no hepatic activation.
Faster onset and shorter duration.
Reversible purine receptor antagonist.

Question 16

What is prescribed when patients are stabilised from MI?

Answer 16

Statins and ACE inhibitors ( spinolactone and eplerenone) and beta blocker.

Question 17

What must be cautious when prescribing beta blocker?

Answer 17

Do not prescribe to patients without left ventricular systolic dysfunction/ HF, who have had MI MORE THAN 12 months.