drugs for coronary heart disease

Question 1

types of angina

Answer 1

1. atherosclerotic angina/ stable angina = atherosclerotic plaques partially occluding arteries
2. vasospastic angina/ rest angina = coronary artery randomly goes into spams and narrows
3. Unstable angina = disruption of atherosclerotic plaque, complicated with partially occlusive thrombosis that gives rise to vasoconstriction and vasospasm

Question 2

Nitrates (vasodilator)

Answer 2

Nitroglycerin (glyceryl trinitrate), glyceryl dinitrate, glyceryl mononitrate

MOA: nitrate oxide donor that causes guanylyl cyclase to be activated = increases cGMP = inactivates myosin-light chain = vasorelaxation
- venodilation reduces preload
- arteriolar dilation reduces afterload
overall reducing O2 consumption and demand

note: dose-dependent effects = low dose only dilates veins, high dose dilates both arteries and veins

note: nitroglycerin has the fastest onset of action, followed by Mononitrate and lastly dinitrate. Onset of action correlates with duration of action.

clinical uses
a. angina pectoris prophylaxis
b. heart failure - mono and dinitrate
c. acute treatment of angina pectoris - nitroglycerin

adverse effects = reflex tachycardia, hypotension, meningeal artery vasodilation causing headache

Question 3

Calcium channel blockers (vasodilator and cardiac depressant)

Answer 3

went through in anti-hypertensive lecture

Question 4

beta-blockers (cardiac depressant)

Answer 4

went through in anti-hypertensive lecture

Question 5

Ivabradine

Answer 5

MOA: “pure” HR lowering agent that binds to a special receptor that directly decreases HR w/o affecting preload or afterload + specific inhibition of cardiac pacemaker I(f) current that controls spontaneous diastolic depolarisation in sinus node = reduce cardiac workload and O2 consumption

clinical uses = stable angina pectoris, chronic heart failure with systolic dysfunction

adverse effects = visual problems (luminous phenomena), bradycardia associated symptoms (dizziness, hypotension)