angina

Question 1

treatment of acute attacks

Answer 1

Organic nitrates

Question 2

Prevention/prophylaxis of angina

Answer 2

organic nitrates, CCBAs, BBs

Question 3

Treatment of underlying conditions of stable angina

Answer 3

• Antiplatelet meds e.g. low dose aspirin
• BP control e.g. ACE inhibitor
• Lipid control e.g. statins

Question 4

Organic nitrates MOA

Answer 4

• Produce smooth muscle relaxation e.g. vascular SM, SM in the GIT and bronchi
• Relaxation of vascular smooth muscle produces vasodilation
• Dilates arteries = reduces preload (makes it easier to pump)
• Dilates veins = reduces afterload (less to pump)
• Dilates coronary vessels
• Cause venous dilation – reduces venous return, preload, cardiac work, 02 demand
• Cause artery dilation – reduces PR, afterload, cardiac work, 02 demand
• Dilates coronary vessels and increases coronary blood flow, particularly to ischamic areas, which increases myocardial 02 supply

Question 5

use of organic nitrates, and discuss their adverse drug reactions

Answer 5

• Too frequent or continuous use of nitrates = tolerance/reduced therapeutic effect

Drug interaction between PDE5 inhibitors and organic nitrates

• PDE5 inhibitors e.g. tadalafil, sildenafil (Viagra) – erectile dysfunction drugs
• Contraindicated – can cause profound hypotension, MI

Question 6

CCB MOA

Answer 6

only dilate arteries, not veins (reduce afterload)

• Artery dilation = reduces peripheral resistance, afterload, cardiac work, o2 demand
• Dilate coronary vessels and increase coronary blood flow which increases o2 supply to the heart muscle
• They don’t affect veins or preload
• Take on a regular basis for the prophylactic treatment of angina, not for acute attacks
• If acute attack of angina occurs – pt needs GTN spray/sublingual tablet

Question 7

Adverse effects CCB

Answer 7

• Nausea, vasodilatory effects including headache, flushing, dizziness, hypotension, peripheral ankle oedema (doesn’t repond to diuretics, not heart/renal related, just a side effect)
• Vasodilatory effects usually subside with continued treatment (may need dose reduction)
• Constipation (Verapamil)
• Bradycardia (Diltiazem, verapamil)

Question 8

BB for angina

Answer 8

• For prophylactic treatment of angina, not for acute attacks
• Initial therapy for angina. CCBA are alternatives – recommended when BB contraindicated
• Reduce HR, BP, cardiac contractility
• Reduce frequency of angina, prolong exercise capacity, decrease risk of adverse cardiac events/mortality
• In diabetes – may mask some signs of hypoglycaemia (tachycardia, tremor)
• Abrupt withdrawal dangerous – severe angina, cardiac arrhythmia, MI, rebound HTN  reduce dose gradually

Adverse effects: bradycardia, hypotension, orthostatic hypotension, worsening of raynauds, fatigue, cold extremities

Non-selective BBs: block both beta 1 + 2 receptors e.g. propranolol
Cardio-selective BBs: selectivity for beta 1 receptors e.g. atenolol, metoprolol