Cardiac Glycosides and Inodilators Flashcards
What two clinical conditions in veterinary practice would you use cardiac glycoside for treatment
dilated cardiomyopathy and endocardiosis
What symptoms are shown with Class 1 congestive heart failure?
only strenous exercise is limited
What symptoms are shown with Class 2 congestive heart failure?
fatigue, shortness of breath, coughing on exercise
What symptoms are shown with Class 3 congestive heart failure?
comfortable at rest but excercise is minimal
What symptoms are shown with Class 4 congestive heart failure?
no capacity for exercise, clinical signs at rest
What drugs can be used for class 2-4 congestive heart failure?
digoxin, pimobendan, ACE inhibitors, and other inotropic drugs
What is the goal of drugs used to treat congestive heart failure?
the goal is to increase stroke volume
What is the problem with digoxin?
getting the dose right
What form of digoxin is the best use?
in a liquid form
What is the mode of action of glycoside?
Glycoside → inhibition of Na/K exchange → Increased Na concentration → decreased Na/Ca exchange → Increased Ca concentration → increased contraction and rate
What are the major actions of cardiac glycosides?
Positive inotropic action - increased force
Negative chronotropic effect - slowing of the heart
Negative dromotropic effect - slowing conduction of the AV node
How do cardiac glycosides create a negative chronotropic effect?
they stimulate the vagus nerve and also improve baroreceptor sensitivity countering sympathetics
What is the half-life and elimination method of digoxin in dogs?
Half-life - 23-39 hours
Elimination - mainly renal
What is the half-life and elimination method of digoxin in cats?
Half-life - 25-78 hours
Elimination - renal
What is the half life and steady state of digoxin in horses?
Half-life - 13-23 hours
Elimination - renal
