Cardio-Ischemic Cardiac Diease Flashcards
What drug class is amlodipine
Noncardioactive calcium channel blocker
What is the mechanism of action for ranolazine
INhibits the late sodium current in cardiomyocytes
What is the the drug class for dipyridamole
Arterial vasodilator
What is the result of ranolazine
- Reduces diastolic tension and compression of coronary vessels in diastole
- Reduces Cardiac contractility and oxygen demand
- Does not affect HR, coronary blood flow
What are the undesired effects of beta blockers or calcium blockers alone
Increase in EDV and ejection time
What are the undesired effects of nitrates alone
Increased HR and contractility via baroreceptor reflex
What drug class is isosorbide mononitrate
Nitrates aka vasodilators
What are the clinical adverse effects of nitrates
- Headache (meningeal vasodilation)
- Orthostatic hypotension
- Sympathetic discharge
- Water and salt reabsorption
What is the mechanism of action for nitrates
1) Nitrates are metabolized to act as donor Nitric oxide
2) Nitric oxide binds to Guanylyl cyclase
3) GTP —> cGMP
4) Potassium channel opens, causing hyperpolarization
5) Hyperpolarization causes decreased calcium entry and subsequent contraction of vasculature
What are the contraindications for beta blockers
- Asthma
- Peripheral vascular disease
- type 1 diabetics
- AV conduction abnormalities
Which patients are nitrates contraindicated
Elevated intracranial pressure
Which drugs will interact with nitrates
Those used for treatment of ED, which are the -afils
What is the mechanism that calcium channel blockers work for angina
Decreased myocardial O2 demand: (atherosclerotic angina)
-Decreased peripheral resistance and afteload and BP
-Arteries more affected than veins
-Decreased cardiac contractility and heart rate (in cardioactive blockers)
Increased blood supply: (variant angina)
-Lilation of coronary arteries relieves the spasms
What drug class is Nicardipine
Noncardioactive calcium channel blocker
What drug class is diltiazem
cardioactive calcium channel blocker
What is the order of vasculature affected by nitrates
Veins> large arteries > small arteries and arterioles
What is the result of combined nitrates and beta blockers
- Decrease in the HR and Atrial pressure
- No change in the EDV, contractility, or ejection time
What is the long acting noncardiactive calcium channel blocker
Amlodipine (half life of 30-50 hours)
What are the adverse effects of nitrate use
Development of tolerance leading to:
- Depletion of thiols
- Increased superoxide radicals and decrease in NO
- Activation of SNS
- Retention of salt and water
What is the treatment in the cause of vasospastic angina
Vasodilators
What drug class is verapamil
cardioactive calcium channel blocker
What drug class is nitroglycerin
Nitrates aka vasodilators
What drug class is isosrbide dinitrate
Nitrates aka vasodilators
What drug class is Nifedipine
Noncardioactive calcium channel blocker
What are the clinical situations that nitrates are used
- Short acting formulas for angina attack
- Long acting formulas for prevention of attack
What is the mechanisms utilized by nitrates during angina
- Overall, decreases the myocardial oxygen demand
- Dilation of veins (main effect by increased venous capacity, reduced preload)
- Dilation of arterioles, but no substantial increased blood flow to ischemic area
What are the adverse effects of beta blockers
- Decreased liver glucose mobilization
- Increased VLDL and decreased HDL
- Sedation and depression
What is the mechanism that beta blockers are successful in treating angina
reduction in myocardial oxygen demand via:
- Decreased blood pressure and afterload
- Decreased heart rate
- Decreased contractility
What are the secondary effects of NO
Blocks:
- LDL oxidation
- Superoxide radicals
- Smooth muscle proliferation
- Monocytes adhesion
- platelet aggregation
What is the mechanism that endothelium can relax the vasculature
Release of endothelium derived relaxing factor (EDRF) by ACh
What type of angina do calcium blocker act and what is the mechanism
Atherosclerotic angina by decreasing the myocardial Oxygen demand
What are the pharmacokinetics of nitrates
- High first pass metabolism due to nitrate reductase in liver
- Isosorbide mononitrate is poor substrate of nitrate reductase and increases bioavailability
What are the adverse effects of calcium channel blockers
- Cardia depression, arrest, acute cardiac failure
- Bradycharia and heart block
- reflex Sympathetic activation
Which patients or conditions are the used of vasodilators not usedful or helpful and what is the reasoning
Atherosclerotic angina aka classical angina
*Because “coronary steal” where the non-occluded vessel will dilate, so the ischemic area will receive less blood low and the normal will receive more than normal
Which drug increases the risk of an MI and in which patients
Fast release Nifedipine increases the risk of MI on a pt with hypertension (medium and slow release are better tolerated)
