Cardiovascular Drugs Flashcards
the cardiovascular system consist of?
- The Heart
- The Blood Vessels
The main function of the cardiovascular system?
To transport blood to from the body tissues
Normal Cardiac Cycle
The atria contracts pushing blood into the ventricles
The ventricles push the blood out to the body tissues
Cardiac muscle contractions is controlled by?
Depolarization of cardiac muscle cells causes contraction
What are the heart valves?
- Tricuspid Valve (Right AV Valve)
- Mitral Valve (Left AV Valve)
Vasodilators are used to?
Prevent vasoconstriction from occurring
Vasoconstriction is the body’s response to?
Low blood pressure due to a failing heart
Why are vasodilators prescribed to patients with congested heart failure?
Renin release system by the kidney is why vasodilators are prescribed to animals w/ congested heart failure to prevent further water retention & increase blood volume. This in return makes the heart stronger but does not reverse the heart failure that has already happened.
What is the most common reason for congestive heart failure in dogs?
Abnormal heart valve. Most commonly an abnormal mitral valve
All vasodilators cause hypotension or hypertension?
Hypotension
Common vasodilator drugs used in vet med?
- Amlodipine
- Hydralazine
- Angiotensin Converting Enzyme (ACE) inhibitors
- Prazosin
- Nitroglycerin
Amlodipine clinical use?
- Used to control high blood pressure in dogs & cats even when no heart issue is associated
- Vasodilators
- Use to prevent vasoconstriction in dogs/cats with congestive heart failure
- Calcium channel blocker that causes relaxation of vascular smooth muscle
Amlodipine is commonly used in what species?
Dogs
Hydralazine is commonly used?
In clinic as an ER drug for congestive heart failure
- Animal in crisis that cannot breathe due to fluid in the lungs
Hydralazine works by?
Causing direct relaxation of vascular smooth muscle by interfering with calcium movement
Angiotensin Converting Enzyme (ACE) Inhibitors clinical use?
Prescribed for long term management of heart failure
*Works by blocking the formation of the Angiotensin II which is responsible for vasoconstriction & sodium retention
Prazosin works by?
Blocking vasoconstrictions by blocking the sympathetic nervous system
Prazosin is commonly prescribed?
- In urethral obstruction as it relaxes the urinary sphincter allowing for easier urination after the animals has been unblocked.
- Not common to prescribe in animals w/ high blood pressure &/or congestive heart failure
Nitroglycerin clinical use?
Common to use on an amergency basis when a patient with congestive heart failure is in crisis
Prescribed for long term management of congestive heart failure
Nitroglycerin formulation?
Topical - Apply to hairless area & use gloves
Nitroglycerin side effects
Hypertension
*Blood pressure monitoring is recommended
Diuretics are used to?
To remove water from the body when the fluid accumulates in unwanted space
Diuretics cause increase?
Urine formation to promote water loss from the body which decreases the volume of blood the heart has to pump
Fluid accusation in the abdomen is a sign of?
right sided heart failure
Fluid accusation in the lungs is a sign of?
Left sided heart failure
Common diuretics used in vet med?
- Furosemide
- Spironolactone
- Thiazide Diuretics
- Mannitol
Furosemide prevents?
Reabsorption of sodium from the renal tubules
Furosemide side effects?
Prolonged use can lead to abnormally low potassium levels
*blood chem panels are recommended to monitor
Spironolactone is considered a?
Aldosterone Antagonist
Spironolactone clinical use?
Congestive heart failure especially if hypokalemia is a concern
*It eliminates the sodium & conserves the potassium
Thiazide Diuretics clinical use?
- More commonly prescribed in humans
- Prevents reabsorption of sodium from the renal tubule
Thiazide Diuretic side effects?
- Prolonged use can lead to abnormally low potassium levels
- Less potent than Furosemide
- Loses effectiveness with long term use
Mannitol is used to?
Treat central nervous system edema from head trauma - swelling in the brain
Mannitol works by?
Creating an osmotic force that keeps water in the renal tubule & prevents water accumulation in the brain especially when inflammation is present after a trauma
Mannitol must be given?
IV
Mannitol should not be given to patients w/
Congestive Heart Failure
Aspirin is used to?
- Prevent platelet aggregation to prevent clot formation
- Reduced change of clot formation
- Mot commonly prescribed anymore
When is aspirin prescribed?
Saddle Thrombis in Cats
Bronchdilators are?
Aminophulline & Theophylline
*Improve contractility by increasing oxygen delivering to the heart muscles
Sedatives & Tranquilzers are used
To decrease sympathetic nervous system stimulation by calming the animal down
