Drugs for Myocardial Ischemia Flashcards
What is the action of the drugs Nitroglycerin, Isosorbide Dinitrate and Isosorbide Mononitrate?
These drugs are all part of the Nitrates used in treating myocardial ischemia.
These drugs function by being reduced to nitric oxide where they can increase cGMP/cGK-1 activation allowing vasorelaxation.
What enzyme activates the followin drugs?
Nitroglycerin, isosorbide dinitrate and isosorbide mononitrate?
mitochondrial aldehyde reductase reduces these drugs to form nitric oxide for vasodilation.
What is the potential risk factor when using NO producing drugs?
There is a very quick tolerance build up with these drugs.
A way of getting around this is to simply discontinue or greatly lower the dose for a few hours a day.
What is the half life of the drug Nitroglycerine?
The half life is 40 minutes.
What is the difference between Isosorbide dinitrate and isosorbide mononitrate?
Dinitrate is rapidly metabolized in around 40 minutes with a T1/2 of 2-4 hours.
Mononitrate does not require any first passmetabolism and has a 2-4 hour half life. Can also be provided in a phasic release form.
What effects do the NO producing drugs have
These depend on the beds of blood they act on.
Serve to:
Vasodilate veins by decreasing ventricular volume and preload.
Have no effect on peripheral vascular resistance.
Have little to no effect on coronary resistance vessels
What are the three indications for organic nitrate use?
Acute angina attacks
Unstable angina and acute myocardial infarction
Congestive heart failure
Why are organic nitrates often the drug of choice for treating acute heart failure?
Because these guys lower filling pressure without causing adverse systemic blood pressure effects.
How does the drug Ranolazine work?
This drug inhibits the late sodium channel facilitating calcium entry.
This ultimately decreases diastolic tension and cardiac contractility.
What is the therapeutic use for the drug Ranolazine?
Acts as an antiarrhythmic drug and also decreases MVO2.
What are the side effects of the drug Ranolazine?
Prolongs the QT interval in patients with coronary artery disease but shortens it in Long QT syndrome patients.
What drug interactions does Ranolazin have?
May interfere with digoxin and simvastatin use!
