Drugs Used In Angina Pectoris and Myocardial Infarction Question And Answers

Drugs Used In Angina Pectoris and Myocardial Infarction Important Notes

1. Classification of nitrates

  • Short-acting
    • Glyceryl trinitrate
    • Nitroglycerine
  • Long-acting
    • Isosorbide dinitrate
    • Isosorbidemononitrate

2. Isosorbidemononitrate

  • Long-acting
  • Undergoes little first-pass metabolism
  • Bioavailability is high

3. Nitrates

  • Its most prominent action is exerted on vascular smooth muscle
  • It dilates veins more than arteries
  • Causes peripheral pooling of blood
  • This decreases venous return
  • Decrease load on the heart

4. Nitroglycerine

  • Used by sublingual route
  • Acts within 1-2 min as it is directly absorbed into the systemic circulation

Drugs Used In Angina Pectoris and Myocardial Infarction Long Essays

Question 1. Classify vasodilators. Describe the pharmacol¬ogical actions of nitrates, their clinical uses, and side effects.


Classification of Vasodilators:

1. Arteriolar dilators – decreases afterload.

  • Hydralazine, Nifedipine, Nicorandil.

2. Venodilators – Decreases preload.

  • Nitrates – Glyceiyl trinitrate, isosorbide dinitrate.

3. Mixed dilators – Decreases both pre and after-load.

  • ACE inhibitors, prazosin, sodium nitroprusside.

Read And Learn More: Pharmacology Question and Answers


  • Nitrates are prodrugs.


1. Preload reduction.

Nitrates dilates veins

Causes peripheral pooling of blood

Decreases venous return

Reduces preload.

2. Afterload reduction.

Nitrates dilate arteries.

Decreases vascular resistance

Decreases afterload.

  • Decreases in preload afterload result in a decrease in cardiac workload.

3. Redistribution of coronary flow.

  • Nitrates relax bigger conducting coronary arteries.
  • Causes redistribution of blood flow to ischaemic areas in angina pectoris.

4. Other vasculature.

  • Dilates cutaneous vessels → causes flushing.
  • Dilates meningeal vessels → causes headache.

Question 2. Enumerate four antianginal drugs that belong to different groups. Write the mechanism of action.


Anti-anginal drugs Classification:

1. Nitrates.

  • Short-acting – Glyceryl trinitrate, Nitroglycerine.
  • Long-acting – Isosorbide dinitrate, Isosorbide mononitrate.

2. Beta blockers.

  • Propranolol, Metoprolol, Atenol.

3. Calcium channel blockers.

  • Verapamil, Diltiazem, Nifedipine.

4. Potassium channel opener- Nicorandil.

5. Others

  • Dipyridamole, Trimetazidine.

Short-Acting Drugs – Nitrates:

  • Short-acting drugs are among nitrates.

Mechanism of Action:

Denitration of organic nitrates in the smooth muscle cells.

Releases reactive free radical nitric oxide.

Causes activation of cytosolic guanylyl cyclase.

Increases cGMP

Causes dephosphorylation of myosin light chain kinase

This interferes with the activation of myosin.

Myosin fails to interact with actin.

No contraction occurs, thus it causes relaxation.

Drugs Used In Angina Pectoris and Myocardial Infarction Short Essays

Question 1. List one cardioselective and one nonselective beta-blocker. Mention two therapeutic uses of them.


1. Cardioselective beta blocker:

  • They selectively block the bl receptor and weakly the b2 receptor.
  • Their inhibition of glycogenolysis is low.
  • Impairs exercise performance to a lesser degree.

Cardioselective Beta Blocker Uses:

  • Safer is diabetics
  • Cardiac arrhythmia.
  • Angina pectoris.
  • Hypertension.

Cardioselective Beta Blocker Examples:

  • Atenolo, metoprolol and esmolo.

2. Non-selective beta blockers.

Non-Selective Beta Blockers Uses:

  • Glaucoma.
  • Anxiety
  • Pheochromocytoma.
  • Thyrotoxicosis.
  • Prophylaxis of migraine.

Non-Selective Beta Blockers Examples:

  • Timolol, propranolol, nadolol, sotalol.

Drugs Used In Angina Pectoris and Myocardial Infarction Short Answers

Question 1. Nitroglycerine.


Nitroglycerine is a short-acting antianginal drug.

Nitroglycerine Mechanism:

Conversion of nitroglycerine to nitric oxide.

Causes relaxation of vascular smooth muscles

Leads to vasodilation.

Reduces venous return and preload on the heart

Nitroglycerine Pharmacokinetics:

  • Effective sublingually.
  • Well absorbed from buccal mucosa.

Nitroglycerine Uses:

  • Angina
  • Cardiac failure
  • Myocardial infarction.
  • Cyanide poisoning.

Question 2. Name drugs causing gingival hyperplasia.


Drugs causing gingival hyperplasia:

1. Anticonvulsants.

  • Phenytoin sodium – phenobarbitone, carbamazepine.

2. Antihypertensive-nifedipine, amlodipine, nimodipine.

3. Immunosuppressants – cyclosporine.

Question 3. Name organic nitrates used in the treatment of angina pectoris.


Organic nitrates used in the treatment of angina pectoris are.

1. Short acting-Glyceryl trinitrate Nitroglycerine.

2. Long-acting – Isosorbide dinitrates, isosorbide mononitrate.

Question 3. Angina pectoris


Angina pectoris is a pain syndrome due to the induction of an adverse oxygen supply-demand situation in a portion of a myocardium.

Angina pectoris Forms:

1. Classical/Stable angina.

  • The attack is provoked by exercise, emotion, and eating.
  • In it, blood flow fails to increase during increased demand despite dilatation of resistance vessels and pain occurs.

2. Variant angina.

  • Attacks occur at rest or during sleep.
  • Occurs due to recurrent localized coronary vaso-spasm in the presence of atherosclerotic coronary artery disease.

Drugs Used In Angina Pectoris and Myocardial Infarction Viva Voce:

1. Nitroglycerine is used by the sublingual route

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