CPRS 67: Treatment of Angina Flashcards
Stable angina means discomfort during _________
Increase myocardial demand for oxygen (e.g. during exercise and emotional stress)
Coronary Atherosclerosis
Unstable Angina means discomfort during _____
Rest
2 big principles for antianginal drugs
- Increase myocardium perfusion by vasodilation of coronary vessels
- Reduce metabolic demand or cardiac workload
What parts should the anti-anginal drugs dilate?
Collateral arteries
What is the coronary steal phenomenon
In angina, the arterioles at the plaque region is already fully dilated due tot he compensatory mechanism
Using non-selective dilators will dilate all other parts of the arterioles except the blocked part (Blocked part cannot further dilate anymore)
It will further reduce the blood supply to the ischemic area and enhance angina.
Name the type of short acting nitrate
Nitroglycerin
Name the type of long acting nitrate
Isosorbide dinitrate
What is the pathway of nitrate to induce vasodilation?
Nitrate becomes nitric oxide Stimulate Guanylyl cyclase GTP => cGMP Dephosphorylation of myosin light chain Relaxation of smooth muscle Vasodilation of collateral artery
What drugs can enhance the effect of nitrate?
Name2
Sildenafil- a PDE inhibitor
Riociguat- guanylyl cyclase stimulator
Which drugs stimulates the cGMP production?
Nicorandil
What are some adverse effects of using nitrate?
Tachyphylaxis
Reflex tachycardia
Postural Hypotension
How does nicorandil work
Stimulate cGMP production => Vasodilation, relaxation of myosin
Activate ATP sensitive K+ Channels, Increase K+ efflux, increase smooth muscle hyperpolarization and vasodilation
Which drug inhibits 3-KAT enzyme in fatty acid beta oxidation pathway
Trimetazidine
How does trimetazidine work
Inhibit 3-KAT enzyme in fatty acid beta oxidation pathway
Body shifts to glucose oxidation for ATP production to increase the efficiency for oxygen utilization
Adverse effect of trimetazidine
Parkinson Syndrome
