EXAM #2: CV PHARM VIII Flashcards
What is the physiologic cause of angina?
Release of BRADYKININ and ADENOSINE onto nociceptive afferents
What is angina?
Retrosternal chest pain radiating to the neck, jaw, or back
What is “stable” angina?
Short-duration anginal pain precipitated by:
- Exercise
- Cold weather
- Stress
What is “unstable” angina?
Longer-standing anginal (~20 min) pain
- Occurs at REST and dissipates with rest
- Crescendos
What are the hallmarks of AMI?
- Sudden onset
- Lasts longer than 30 min.
- Associated with dyspnea, weakness, nausea, and vomiting
What are the two general approaches to altering myocardial oxygen consumption to decrease angina?
1) Decrease myocardial oxygen demand
2) Increase myocardial supply
What classes of drugs decrease myocardial oxygen demand?
Beta-blockers
Ca++ blockers
Organic nitrates
Ca++ entry blockers
What are the classes of drugs that increase myocardial oxygen supply?
Vasodilators
Statins
Anti-thrombics
List the organic nitrates that are used for myocardial ischemia.
Nitroglycerin
Isosorbide Dinitrate
Isosorbide Mononitrate
What enzyme activates organic nitrates?
mitochondiral aldehyde reductase
What is the mechanism of action of the organic nitrates?
1) NO increases cGMP 2 cGMP activates cGK-1, which: - Increased mitochondrial Ca++ uptake - Decreases Ca++ influx - Phosphorylates MLCK
What is the effect of MLCK phosphorylation?
Myosin Light Chain Kinase= MLCK
- Phoshorylation of MLCK inhibits its activity
- When phosphorylated, MLCK cannot activate
Myosin Light Chain, which would cause vasoconstriction
Thus, MLCK phosphorylation causes VASORELAXATION
What is nitrate tolerance? What are the clinical implications?
Sustained organic nitrate therapy reduces the efficacy of the drugs
Thus, in patients that need this therapy, a bridge with a different class drug for part of the day is recommended
Describe the half life to NTG.
Undergoes hepatic and intravascular metabolism v. quickly
**T1/2 is 1-4 minutes
What is the advantage of Isosorbide Dinitrate?
Available in a sustained release form that allowing for dosing once daily
–>Avoids nitrate tolerance