Cardiovascular Drugs Flashcards
What are the B1 Agonists
Dopamine
Epinephrine
Norepinephrine
Isoproterenol
What are the Cardiac Stimulants
B1 Agonists
Phosphodiesterase inhibitors
Glucagon
Calcium salts
What are the positive inotropic drugs
Digitalis glycosides
B1 agonists
What are the digitalis glycosides
Digitoxin
Digoxin
Ouabain
How is digoxin given
Oral
Slow IV in emergency
When is digoxin used
CHF
Atrial arrhythmias in dogs
How does Digoxin work
Inhibition of Na-K ATPase in myocardial cell
Increases Na exchange with Ca –> increased intracellular calcium
What are the effects of digoxin
Decreased sinus rate
Slowing of AV conduction
Prolonged PR intervals
Increased heart efficiency, normalized BP
How is digoxin excreted in dogs and horses
Renal
How is digoxin excreted in cats
Renal and Hepatic
Adverse effects of digoxin
Acute hyperkalemia
Chronic hypokalemia
Arrhythmias
What is an inodilator
Positive inotrope and balanced vasodilator
What is the major inodilator
Pimobendan
How is Pimobendan given
Oral
60% bioavailability
Pimobendan enhances the interaction between ___ and ___ leading to ___
Ca and troponin C
Increase in intracellular Ca and myocardial oxygen consumption
Pimobendan inhibits ___ leading to __
PDE 3
Balanced vasodilation
Decreased cardiac preload and afterload
What is Pimobendan used for
CHF in dogs
Improves life quality and length for DCM and CVD
Adverse affects of Pimobendan
Diarrhea, vomiting, inappetence, seizures, PU/PD
Pimobendan is less arrhythmogenic than digitalis T/F
True
Do not use Pimobendan w/
Hypertrophic cardiomyopathy
Where CO increase is not physically possible
Vasodilators for CHF
ACE inhibitors - Enalapril
Hydralazine
Nitrates
Prazosin
Diuretics used in CHF
Loop diuretics - furosemide
Thiazide diuretics
Potassium retaining diuretics - spironolactone
Blocking B1 results in
Indirect vasodilation
Inhibit renin and angiotensin 2
Main Beta Blocker
Carvedilol
What does carvedilol do
Non-selective B-blocker and alpha 1 blocker
Antioxidant inhibits endothelin release
Reduces harmful effects of SNS
What is carvedilol primarily used for
Early CHF due to dilated cardiomyopathy
Adverse effects of carvedilol
Hypotension
Bradycardia
Hyperkalemia
Causes of arrhythmias
Imbalances of sympathetic and parasympathetic
Changes in serum K, Ca, Mg
Hypoxemia, acidosis, Trauma, drugs
CHF, cardiac ischemia, infarction
Tachyarrhythmia Class 1 a/b
Sodium channel blockers
A - prolongs action potential
B - shortens action potential
Tachyarrhythmia Class 2
B-blockers - drug of choice for cats
Tachyarrhythmia Class 3
Agents that prolong action potential duration (K blocker)
Tachyarrhythmia Class 4
Ca channel blockers
Quinidine - Class and function
Class 1 A
Prolonged action potential
Quinidine is used for
Ventricular arrhythmias
Atrial fibrilation in horses
Procainamide - class and function
Class 1A
Prolonged action potential
Procainamide is used for
Ventricular arrhythmias
Lidocaine - Class and function
Class 1B
Shortens action potential
Lidocaine is used for
Intravenous drug of choice for ventricular arrhythmias due to general anethetics, surgery, ischemia, trauma
Digitalis induced arrhythmias
Phenytoin - Class and function
Class 1B
Shortens action potential
Phenytoin is used for
Digitalis induced arrhythmias in dogs
Propranolol class
Class 2 - beta blocker
Propranolol is used for
paroxysmal supraventricular tachycardia
Digitalis induced tachyarrhythmias
Arrhythmias due to inhalation anesthesia
Verapamil and Diltiazem Class
Class IV - Ca channel blocker
Verapamil and Diltiazem are used for
Supraventricular tachyarrhythmias
Myocardial hypertrophy
Types of Supraventricular Tachyarrhythmias in Dogs
Atrial Tachycardia
Atrial flutter
Atrial Fibrillation
Drugs used for Atrial Tachycardia
Digoxin Procainamide Propranolol Quinidine Phenytoin
Drugs used for Atrial Flutter
Digoxin
Quinidine
Procainamide
Propranolol
Drugs used for Atrial Fibrillation
Digoxin
Propranolol
Quinidine
Procainamide
Ventricular Arrhythmias in Dogs
Ventricular Premature Complexes
Ventricular Tachycardia
Drugs used for Ventricular Premature Complexes
Quinidine Procainamide Lidocaine Phenytoin Propranolol
Drugs used for Ventricular Tachycardia
Procainamide Lidocaine Quinidine Phenytoin Propranolol
What is the drug of choice for CATS with Supraventricular or Ventricular Tachyarrhythmias
Beta Blockers
Bradyarrhythmias in Dogs
Sinus bradycardia
Second degree AV block
Cardiac Asystole (Cardiac resuscitation)
Drugs used for Sinus Bradycardia
Atropine
Isoproterenol
Drugs used for Second Degree AV Block
Atropine (best)
Isoproterenol
Glucagon
Drugs used for Cardiac Asystole (cardiac resuscitation)
Epinephrine
Non-Selective Alpha agonists - Used for and drugs
Vasoconstriction - hypotension
Epinephrine and Norepinephrine
Selective Alpha1 agonists - used for and drugs
Vasoconstriction - hypotension
Phenylephrine
Direct and Indirect Sympathomimetics - used for and drugs
Vasocontriction - hypotension
Epinephrine
Pseudoephedrine
Phyenylpropanolamine
Vasodilators are used for
Hypertension, CHF, Thrombosus
Vasodilation drug types
Sympatholytic drugs ACE Inhibitors Angiotensin II antagonists Direct acting vasodilators Calcium channel blockers
Non-selective Alpha blockers - Class, use and Drugs
Sympatholytic Vasodilator
Emergency hypertension, hypertensive crisis
Phentolamine
Phenoxybenzamine
Selective Alpha1 Blocker - Class and Drugs
Sympatholytic Vasodilator
Prazosin, Terazosin, Doxazosin
Presynaptic Alpha2 Agonist - Class and Drugs
Sympatholytic Vasodilator
Clonidine
Non-Selective Beta Blockers - Class and Drugs
Sympatholytic Vasodilator
Propranolol
Selective Beta1 Blockers - Class and Drugs
Sympatholytic Vasodilator
Atenolol
Beta and Alpha Blocker - Class and Drugs
Sympatholytic Vasodilator
Carvedilol
ACE Inhibitors
Captopril, Enalapril, Benazepril, Lisinapril
ACE Inhibitors are all given only orally except
Enalapril - also given parenterally
What do ACE Inhibitors Block
Kininase (angiotensin converter)
Angiotensin II synthesis
Aldosterone
What do ACE Inhibitors Increase
Renin and Bradykinin
What are ACE Inhibitors used for
CHF, Hypertension, Chronic Renal Insufficiency in Cats
Which two ACE Inhibitors are Long Acting
Benazepril and Lisinapril
Which two ACE Inhibitors are liver activated
Enalapril and Benazepril
Enalapril has a slower onset and longer duration than ___ in the dog
Captopril
Captopril absorption is reduced by
Food
Which ACE Inhibitor has significant excretion in bile (50%)
Benazepril
Captopril has more GI side effects than ___
Enalapril
Adverse Effects of ACE Inhibitors
Hypotension
Decreased glomerular pressure –> decreased GFR, hypertension, azotemia
Captopril may cause what in some dogs
Idiosyncratic glomerular disease
Angiotensin II Antagonist Drug
Losartan
Angiotensin II Antagonist used for
Antihypertensive
Hydralazine is a
Direct acting arteriolar vasodilator
Hydralazine increases
Local concentrations of PGI2
Mechanism of Action of Nitrates
Formation of NO activating guanylyl cyclase
Increases cyclic GMP
Relaxation of blood vessel smooth muslce
Calcium Channel Blockers
Diphenyl Alkylamines - Verapamil
Benzodiazepines - Diltiazem
Dihydropyridines - Amlodipine, Nifedipine
Ca Channel Blockers Mechanism of Action
Inhibit influx of extracellular Ca across myocardial and smooth muscle cell membranes –> inhibits myocardial contraction and dilates arteries
Ca Channel Blockers Effects on the Heart
Negative inotropic/chronotropic effect
Increase O2 delivery to myocardial tissue
Decrease afterload
Coronary vasodilation
Ca Channel Blockers Effects on the Blood Vessels
Decrease peripheral resistance
Decrease Systemic BP
Antiarrhythmic Class IV - Drugs and Use
Verapamil and Diltiazem
Supraventricular Tachyarrhythmias
Antihypertensive Drugs and Use
Amlopdipine
First line antihypertensive in cats unless caused by hyperthyroidism
If Hypertension in cats is caused by hyperthyroidism which drug should be used
Beta Blocker
Myocardial Hypertrophy - Drug and species
Diltiazem
Cats - first choice
Adverse Effects of Ca Channel Blockers
Bradycardia and AV Block
Hypotension
GI Side Effects
Elevated liver enzymes
Antihypertensive Drugs - Diuretics
Hydrochlorothiazide
Furosemide
Antihypertensive Drugs - Beta Blockers
Propranolol
Atenolol
Antihypertensive Drugs - Vasodilators
ACE Inhibitors
Angiotensin II Antagonists
Hydralazine
Alpha blockers
Drugs for Emergency Hypertension (hypertensive Crisis)
Hydralazine Propranolol, Acepromazine IV Phentolamine Oral Calcium channel blockers Prazosin ACE Inhibitors