Anti- Anginal Drugs

Question 1

Name the 4 types of Anti- Anginal drugs

Answer 1

Beta Blockers Ca2+ Channel Antagonists Nitrates Potassium channel openers

Question 2

What are the two types of beta blockers and give an example of both types

Answer 2

Cardioselective - Atenolol Non- Selective - Propanolol

Question 3

What are the two types of Ca2+ Channel Antagonists and give an example of both types

Answer 3

Dihydropyridines - Amlodipine Rate limiting calcium antagonists - Verapamil & Diltiazem

Question 4

Give 2 examples of Nitrates

Answer 4

Glyceryl trinitrate Spray (GTN Spray) Isosorbide mononitrate

Question 5

Give 2 examples of Potassium channel openers

Answer 5

Nicorandil Ivabradine

Question 6

What is the mechanism of Beta blockers

Answer 6

Reduce Hr and Force, esp. during exercise or stress. Coronary vessel diameter is marginally reduced, but myocardial O₂ requirement falls – so better oxygenation of the myocardium

Question 7

What is the mechanism of Ca2+ channel antagonists

Answer 7

α1 receptors are blocked, reducing their effects and causing vasodilation. Cause peripheral arteriolar dilatation, ↓ afterload and myocardial O₂ requirement and Coronary Vasodilatation

Question 8

What is the mechanism of Nitrates

Answer 8

Relax all types of smooth muscle, via their metabolism to nitric oxide. Small doses – vasorelaxation - ↓ CVP (preload) reduces SV Higher doses - ↓ MAP - ↓ afterload ↑ Coronary blood flow. In angina, there is no overall increase, but blood is directed towards the ischaemic zone – collateral arterioles dilated >> ↓myocardial O₂ req., ↓ afterload, ↑Ischaemic perfusion

Question 9

What is the mechanism of Potassium channel openers

Answer 9

↓ The Ca2+ sensitivity of smooth muscle, Activates sarcolemma Ca2+ pump and promotes K+ efflux, causing hyperpolarization → relaxation of the smooth muscle and coronary vasodilation

Question 10

What conditions can Beta blockers be used for

Answer 10

Cardioselective - Angina, Heart Failure, Hypertension Non- Selective - Also Thyrotoxicosis

Question 11

What conditions can Ca2+ Channel Antagonists be used for

Answer 11

Hypertension Angina Supraventricular Arrhythmias (RLCA’s)

Question 12

What conditions can Nitrates be used for

Answer 12

Angina GTN - short term relief Isosorbide mononitrate - Longer-acting (t1/2) – resistant to first pass metabolism

Question 13

What conditions can Potassium channel blockers be used for

Answer 13

Nicorandil - Stable Angina Ivabradine - Chronic Heart Failure, Angina Pectoralis

Question 14

What are the side effects of beta blockers

Answer 14

Tiredness Cold Peripheries Can cause Heart failure in the long term Bradycardia Fatigue – CO (β1) and skeletal muscle perfusion (β2) in exercise are regulated by adrenoceptors

Question 15

What are the side effects of Ca2+ channel antagonists

Answer 15

Ankle oedema Hypotension Dizziness Amlopidine better as less unwanted effects on cardiac muscle

Question 16

What are the side effects of nitrates

Answer 16

Repeated Administration may be associated with diminished tolerance. Build in ‘nitrate low’ periods. Postural hypotension Headaches leave 8hrs of the day nitrate free

Question 17

What are the side effects of Potassium channel openers

Answer 17

Hypovolaemia – low systolic BP Palpitations, Weakness