Antianginal Drugs

Question 1

Classification

Answer 1

1. Nitrates
2. Beta- adrenergic blockers
3. Calcium channel blockers
4. Potassium channel opener
5. Others - Antiplatelet agents, Statins,

Question 2

Organic nitrates

MOA

Answer 2

Release nitric oxide > Stimulate guanylyl cyclase > Increased cGMP > dephosphorypation of myosin kinase, decrease in ca conc in cytosol > relaxation of vascular smooth muscle fibres

Question 3

Organic nitrates

Therapeutic uses

Answer 3

1. Angina :
   a. For acute attack of angina
   b. For prophylaxis of angina
2. Variant angina
3. Unstable angina:
   a. Antiplatelet agents
   b. Anticoagulants
   c. Nitrates
   d. B-blockers
   e. CCBs
   f. Statins
4. MI
5. CCF
6. Hypertensive emergency
7. Biliary colic
8. Cyanide poisoning

Question 4

Cyanide poisoning

Answer 4

Step 1 - Amyl nitrate and sodium nitrate. Nitrates convert haemoglobin to methaemoglobin.

Step 2 - Methaemoglobin combines with cyanide to form non toxic cyanomethaemoglobin.

Step 3 - Intravenous sodium thiosulphate converts cyanomethaemoglobin to sodium thiocyanate which is rapidly excreted in urine.

Question 5

Calcium channel blockers

Answer 5

1. Phenylalkylamine - Verapamil
2. Benzothiazepine - Dilitazem
3. Dihydtopyridines - Nifedipine, amlodipine, nicardipine.

Question 6

Calcium channel blockers

MOA

Answer 6

Ccbs block voltage sensitive L type ca channels by binding to alpha 1 subunit > Prevent entry of ca into cell > No excitation contraction coupling

Question 7

Therapeutic uses of CCBs

Answer 7

1. Exertional angina
2. Variant angina
3. Unstable angina
4. Suprabemtricular arrhythmias
5. Hypertension
6. Hypertrophic cardiomyopathy
7. Migraine
8. Raynauds phenomenon

Question 8

Potassium channel openers

Answer 8

Nicorandil

Question 9

Combination Theory

Answer 9

1. Nitrates + beta blockers
2. Nifedipine DHPs + beta blockers
3. Beta blockers + verpamil/dilitazem
4. CCB+ nitrates
5. Nitrates + b blockers + CCBs
6. Sildenafil/tadalafil PDE 5 inhibitors+ nitrates

Question 10

Acute myocardial infarction pharmacotherapy

Answer 10

1. Antiplatelet agent - Aspirin, clopidogrel.
2. Analgesia - Intravenous morphone
3. Nitrates - Intravenous nitroglycerin
4. Low flow oxygen therapy
5. Reperfusion therapy - PCI or thrombolytic therapy.
6. Anticoagulants - low molecular weight heparin
7. Beta blockers during first 24 hours unless contraindicated.
8. ACE Inhibitors or ARBs
9. Statins
10. Treatment of acidosis