Drugs For Angina Pectoris Flashcards
What is the MOA of nitroglycerin?
It acts directly on vascular smooth muscle to promote vasodilation. It acts mainly on veins with modest dilation of arterioles.
How is nitroglycerin used in stable angina?
It decreases the pain of exertional angina mainly by decreasing cardiac oxygen demand.
How is oxygen demand decreased with nitroglycerin use?
It decreases venous return to the heart and thereby decreases ventricular filling resulting in a decrease in wall tension (preload) which decreases oxygen demand.
What actions does nitroglycerin possess in variant angina?
Coronary artery spasms occur in variant angina. Nitroglycerin acts by relaxing or preventing spasm in coronary arteries and increases oxygen supply. It does not reduce oxygen demand in variant angina.
Since patients can develop tolerance to nitroglycerin, how should be prescribed?
They should be used in the lowest effective dosages. Patches and SR preparations should be used on an intermittent schedule that allows AT LEAST 8 DRUG FREE HOURS EVERY DAY, which is usually best at night.
How often should nitroglycerin patches be removed?
They should be removed after 12-14 hours to avoid tolerance.
How should angina be managed during nitrate-free intervals?
With sparing use of a short-acting nitrate such as SL. A beta blocker or CCB can be added to the regimen.
Can nitrate tolerance be reversed?
Yes, by withholding nitrates for a short period of time.
When should rapid onset nitrates such as a SL tablet or the translingual spray be used?
For termination of an ongoing attack and also for short-term prophylaxis before an anticipated exertion such as an exercise.
What are indications for long-acting nitrates?
Prevention of anginal attacks
What does initial treatment of chronic stable angina consist of?
Sublingual nitroglycerin plus a long-acting antianginal drug. Beta blockers are the preferred agents for baseline therapy because they can decrease mortality, especially in pts with a prior MI. They also suppress nitrate-induced reflex tachycardia.
What are the first line drugs for angina of effort? Why?
Beta blockers. They increase exercise tolerance and decrease the intensity of the angina’s attacks. Must be given on a fixed schedule.
What would be a safe beta blocker to prescribe to a patient with asthma?
A bet 1 selective agent such as METOPROLOL.
Why should beta blockers be used with caution in diabetic patients?
They can mask the signs of hypoglycemia (fast heartbeat/palpitations and tremors). Beta blockers block the effect of norepinephrine resulting in slowing of the heart rate and a decrease of tremors.
How does beta blockers affect glycogenolysis?
It can suppress the process the glycogen is broken down into glucose to provide energy and maintain blood glucose levels during fasting (such as between meals).
