SMALL ANIMALS DRUGS FOR TREATING CARDIAC DISEASE

Question 1

drugs for treating heart failure

Answer 1

-decrease preload
-decrease afterload
-enhance inotropic function

Question 2

drugs that decrease preload, indication; excessive preload-signs of

Answer 2

congestion: pulmonary edema, pleural effusion, ascites
>diuretics
>venodilators

Question 3

drugs that decrease preload: diuretics - increase excretion of

Answer 3

sodium > reduction in extracellular fluid volume > lower circulating fluid volume > reduction in preload

Question 4

classes of diuretics

Answer 4

3 classes:
1. loop
2. thiazide
3. potassium sparing

Question 5

diuretics side effects

Answer 5

-polyuria
-polydipsia

Question 6

diuretics complications

Answer 6

-hypotension
-azotemia
-hypokalemia(loop), hyponatremia

Question 7

furosemide, torsemide

Answer 7

=loop diuretics
>blockade of Na+/K+/2Cl-
>loop of Henle
(most potent 25%)

Question 8

hydrochlorothiazide

Answer 8

-thiazide
>blockade of Na+/Cl- carrier
>distal tubule and connecting segment

Question 9

furosemide drug that decrease preload-diuretics: first line therapy for patients with signs of

Answer 9

congestion

Question 10

furosemide: patients can become refractory to drugs to drug with chronic treatment

Answer 10

-higher doses
-coadministration of diuretics that act at different sites in nephron
-substitute for torsemide

Question 11

spironolactone-drugs that decrease preload: diuretics: aldosterone receptor

Answer 11

antagonist
-insufficient natriuretic potency to be used as sole diuretic
-benefits well regocnized
>cats: cutaneous adverse drug reactions

Question 12

drugs decrease preload: ventilators: nitroglycerin: treatment of

Answer 12

acute heart failure ( with loop diuretic)
-transdermal
-adverse effects: rashes at application site, hypotension, headache

Question 13

drugs that decrease AFTERLOAD: vasodilators: left ventricular afterload reduction:

Answer 13

systemic vasodilation
>nitroprusside
-ACEI-angiotensin converting enzyme inhibitors
>pimobendan: Ca channel blockers
-complications: hypotension

Question 14

drugs that decrease AFTERLOAD: vasodilators: right ventricular afterload reduction:

Answer 14

pulmonary vasodilation
-indication: pulmonary hypertension
>slidenafil: phosphodiesterase V inhibitor
>pimobendan can have pulmonary vasodilatory properties

Question 15

drugs that decrease AFTERLOAD: vasodilators: 1. nitroprusside and 2. ACEI and 3. Ca channel blockers

Answer 15

1. balanced effect: preload reduction via ventilation and afterload reduction via arteriodilation, CRI, only in ICU setting (Intensive Care Unit), indications: acute/severe hypertension, acute heart failure, combo with dobutamine
2. ACEI: enalapril, benazepril, inhibition of angiotensin converting enzyme : vasodilation, inhibit fluid retention, part of chronic therapy for heart failure
3. Ca channel blockers: amlodipine: systemic hypertension, in dogs also as afterload reducer for refractory heart failure

Question 16

drugs that enhance inotropic function: myocardial contractility is frequently

Answer 16

impaired in patients with heart failure
> increased cardiac contractility > increased cardiac output, indirectly decreased preload

Question 17

enhance inotropic function: dobutamine used in

Answer 17

acute treatment of heart failure

Question 18

enhance inotropic function: pimobendan used in

Answer 18

chronic treatment of heart failure

Question 19

enhance inotropic function: digoxin treatment for

Answer 19

atrial fibrillation

Question 20

enhance inotropic function: dobutamine indications

Answer 20

-acute signs if heart failure + hypotension / primary failure of myocardial contractility

Question 21

enhance inotropic function: dopamine

Answer 21

adrenergic /dopaminergic inotropic agent

Question 22

dopamine indications

Answer 22

in ICU setting severe hypontension/shock due poor cardiac contractility and / or vasodilation, hypotension during general anesthesia
(dobutamine preferred)

Question 23

drugs enhance inotropic function: Pimobendan

Answer 23

=INODILATOR
-phosphidiesterase inhibiton and calcium sensitization: inotropic and casodilatory properties = INODILATOR

Question 24

pimobendan indications

Answer 24

-most dogs, some cats with heart failure
-dogs with preclinical heart disease

Question 25

anti arrhythmic therapies : Vaughan williams system classes 1-4

Answer 25

-class 1: block Na channels, depress depolarization ; Class 1a-1c -class 2: antiadrenergic drugs: mainly beta adrenergic receptor blockers: indications : atrial tachyarrhythmias AF -class 3: prolong repolarization,indications: ventricular arrhythmias, supra ventricular arrhythmias -class 4: Ca channel blockers, indications: atrial tachyarrhythmias

Question 26

adverse effects of antiarrthythmic therapy

Answer 26

-arrhythmias -cardiac systolic and diastolic function -many class 1 drugs have CNS and GI effects

Question 27

mexiletine: class 1b: similar to lidocaine but less rapid

Answer 27

hepatic metabolism and longer elimination half life -indicaiton: chronic therapy of ventricular tachyarrhythmias in dogs -class 1b neurotoxic to cats

Question 28

lidocaine: class 1b: first choice for treatment of

Answer 28

ventricular tachyarrhythmias -hypokalaemia : poor response to lidocaine -adverse effects: cats prone neurotoxicity>lower dose , GI effects

Question 29

beta adrenergic blockers: class 2: action

Answer 29

reduced heart rate and excitability -indications : supraventricular and ventricular tachuarrhythmias -adverse effects: lethargy, collapse, bradycardia, hypotension most used: atenolol, metoprolol

Question 30

sotalol: class 3 (+class 2 action)- prolong

Answer 30

repolarization + beta 1 and 2 blocker -indication: ventricular and supraventricular tachyarrhythmias: most often used in boxers with arrhythmogenic cardiomyopathy -dogs ventricular tachycardia use lidocaine and procainamide >adverse effects: negative inotropy

Question 31

diltiazem: class 4

Answer 31

Ca channel blockers >actions: slow sinus rate and AV node conduction, arteriodilator >indication: supraventricular tachyarrhythmias >adverse effects: bradycardia (dogs), vomiting (cats)

Question 32

digoxin: digitalis glycoside DG : actions with

Answer 32

heart failure > increased myocardial contractility and cardiac output, diuresis, reduction of edema, reduction heart size, HR >indication: dogs with atrial fibrillation + CHF >adverse effect: arrhythmias, worsening HF

Question 33

antithrombotic drugs: prevention of

Answer 33

arterial thromboembolism

Question 34

antiplatelet drugs: inhibition of platelet aggregation

Answer 34

-aspirin NSAID -clopidogrel

Question 35

sedative/analgetic agents

Answer 35

-butorphanol: opioid agonist/antagonist > decrease stress (acute CHF) -mu agonist (fentanyl)-severe pain (FATE)

Question 36

drugs used in CPR

Answer 36

-reversals: opioids-naloxone -vasopressors: maintain perfusion to vital organs