Pharmacology: Katzung Drugs used in the treatment of Angina Flashcards
What are the two basic strategies used in angina treatment?
(1) Reduction of the mycocardial oxygen demand
(2) Increase in myocardial oxygen delivery.
What is the major determinant of myocardial oxygen requirement?
Myocardial fiber tension
What two factors determine diastolic filling pressure (Preload) and what controls them?
(1) blood volume (fluid retention)
2) venous tone (sympathetic outflow
What two factors determine afterload (systolic pressure)?
(1) areterial pressure
(2) large artery stiffness
To what class of drugs do Nitroglycerin SL, and isosorbide dinitrate SL belong to?
Nitroglycerin and isosorbide are short acting nitrates
What is the MOA for nitroglycerin and isosorbide?
They release NO thus increasing cGMP and relaxing smooth muscle particularly in vascular smooth muscle.
What are the clinical applications for nitroglycerin and isosorbide?
(1) Acute angina pectoris
(2) acute coronary syndrome
What toxicities are associated with nitroglycerin and isosorbide?
(1) Tachycardia
(2) orthostatic hypotension
(3) headache
What differentiates isosorbide from nitroglycerin?
Isosorbide is longer acting (20-30 min) than nitroglycerin (1-15 min)
To what class of drugs do oral nitroglycerin, oral isosorbide dinitrate, and oral isosorbide mononitrate belong to?
They are intermediate acting nitrates
What is the MOA of oral nitroglycerin, oral isosorbide dinitrate, and oral isosorbide mononitrate?
They release NO and mediate vascular smooth muscle relaxation.
What is the clinical application for oral nitroglycerin, oral isosorbide dinitrate, and oral isosorbide mononitrate?
prophylaxis of angina
What toxicities are associated with oral nitroglycerin, oral isosorbide dinitrate, and oral isosorbide mononitrate?
(1) tachycardia
(2) Orthostatic hypotension
(3) Headache
What is transdermal nitroglycerin used for?
transdermal nitroglycerin is a long acting nitrate used in the prophylaxis of angina.
What is amyl nitrite?
it is an ultra short acting nitrite that is inhaled as a vapor. it has a duration of action of 1-5 min. It is obsolete for medical purposes but is sometimes used for recreation.
What are the cardiovascular effects of the nitrates?
They reduce myocardial oxygen demand by reducing cardiac output through reduced venous return to the heart (decreased preload). Nitrate reduced blood pressure may cause reflex tachycardia.
What drug-drug interactions are important to consider when giving nitrates?
Nitrates interact with sildenafil and similar drugs used for erectile dysfunction. They inhibit PDE5 which metabolizes cGMP in smooth muscle. These drugs will synergize with nitrates to cause dangerous hypotension.
Which calcium channel blockers are used in the treatment of angina pectoris?
Verpamil, Diltiazem, Nifedipine, Amlopidine, Felodipine, nicardipine, nisoldipine,
What is the MOA for verpamil and diltiazem?
The block L-type Ca channels in smooth muscle and heart. This decreases intracellular Ca and decreases the force and rate of contraction.
What are the clinical uses for Verpamil and diltiazem?
(1) Stable atherosclerotic Angina
(2) Vasopsastic prinzmetal angina
(3) hypertension
(4) Nodal arrythmias
(5) migraine
What are the adverse effects that are associated with verpamil and diltiazem?
(1) Constipation
(2) pre tibial edema
(3) Flushing
(4) dizziness
(5) Cardiac depression (higher doses)
(6) Hypotension (higher doses)
What is the mechanism of action for nifedipine, amlopidine, felodipine, nicardipine, and nisoldipine?
They are dihydropyridine Ca channel blockers that have more vascular than cardiac effect.
What are the clinical applications for nifedipine, amlopidine, felodipine, nicardipine, and nisoldipine?
(1) angina
(2) hypertension
What are the adverse effects associated with nifedipine, amlopidine, felodipine, nicardipine, and nisoldipine?
(1) Constipation (less than verpamil)
(2) pre tibial edema
(3) Flushing
(4) dizziness
(5) Cardiac depression (higher doses) (less than verpamil)(May actually cause reflex tachycardia)
(6) Hypotension (higher doses)
