Small Animal Clinical Pharmacology - CYF MEDICAL DISTRIBUTION

CHAPTER 17 DRUGS USED IN THE MANAGEMENT OF HEART DISEASE AND CARDIAC ARRHYTHMIAS
Table 17.2 Cardiovascular pharmacology overview
Category Common drugs Common indications
Afterload reducers
Preload reducers
Positive inotropes (↑ strength of
contraction)
Positive lusiotropes (improve
relaxation)
Positive chronotropes (↑ heart rate)
Negative chronotropes
Vasopressors (peripheral
vasoconstriction)
Neurohumoral modulators
Antiarrhythmics:
Class I (#1–4)
Class II (#5)
Class III (#6&7)
Class IV (#8)
Other (#9)
1. Hydralazine [O;****;2]
2. ACE inhibitor [O;*;2]: e.g. enalapril, benazepril
3. Calcium channel blocker: amlodipine [O;****;4]
4. Pimobendan [O;***;2]
5. Nitroprusside [I;*****;1]
A. Diuretics:
1. Furosemide [O,I,S,M;*****;5]
2. Spironolactone [O;*;1]
3. Thiazides [O;**;2]
B. Venodilators
1. Nitroglycerin [I;T;*;1]
2. Pimobendan [O,**,2]
1. Digoxin [O;1/4*;1]
2. Pimobendan [O; ****;5]
3. Adrenergic agonists: e.g. dobutamine
[I;*****;4], epinephrine [1;***,2]
1. Ca channel blocker: diltiazem [O;***;2]
2. β-blocker: atenolol [O;**;3], carvedilol [O;**;1]
1. Adrenergic agonists: dobutamine [I;***;2],
isoproterenol [I,****;2]
2. Anticholinergics [I,S,M;****;4]: atropine,
glycopyrrolate
1. β-blocker [O;***;2]: atenolol, carvedilol
2. Ca channel blocker: diltiazem [O;***;3]
3. Digoxin [O;**;2]
4. Amiodarone [O;***;4]
1. Adrenergic agonists: dopamine, [I,***,2],
epinephrine [I;***;2]
2. Vasopressin [I;***;3]
1. β-blockers: carvedilol [O;***;4]
2. ACE inhibitors [O;****;5]: enalapril
3. Aldosterone antagonist: spironolactone [O;**;4]
4. Digoxin [O;**;2]
1. Lidocaine [I;*****;5]
2. A Procainamide [I,M;***;4]
B Procainamide [O;**;2]
3. Quinidine [O,I;***;2, only horses)
4. Mixelitine [O;***;2]
5. β-blockers [O;**;2]
6. Amiodarone [O,I;****;4]
7. Sotalol [O;****;4]
8. Ca channel blocker: diltiazem [O,I;***;4]
9. Digoxin [O;**;2]
1. Systemic hypertension
2. Systolic dysfunction:
– Dilated cardiomyopathy (DCM)
– Chronic valvular disease (CVD)
1. Left-sided and right-sided congestive heart
failure (CHF)
Note: spironolactone may be more useful in
right heart failure
1. Systolic dysfunction:
– DCM
– CVD
1. Diastolic dysfunction:
– Hypertrophic cardiomyopathy (HCM)
1. Hemodynamically important
bradyarrhythmias, e.g. sinus bradycardia, AV
block
1. Tachycardia: atrial fibrillation and other
hemodynamically significant supraventricular
arrhythmias
Note: often require combination therapy, e.g.
digoxin and diltiazem
1. Hypotension that is unrelated to low cardiac
output, e.g. shock, endothelial dysfunction
1. This category of medication is used in an
attempt to delay the progression of both
preclinical and clinical heart disease and
combination therapy may be superior to
monotherapy, e.g. ACE inhibitor + β-blocker
Dog: DCM and CVD
Cat: cardiomyopathies
1. Acute ventricular arrhythmias (VA)
2. A Acute supraventricular arrhythmias (SVA)
B Chronic VA
3. Atrial fibrillation
4. Chronic VA (better in combination with 5)
5. Chronic SVA and VA (usually in
combination)
6. Chronic and acute SVA and VA
7. Chronic VA (especially boxers)
8. Acute and chronic SVA
9. Chronic SVA (best in combination with 5
or 8)
[Route of delivery; Relative potency in category as monotherapy; Author preference/frequency of use within category], where route of
administration (O, oral; I, IV; S, SQ; M, intramuscular; T, topical), Relative drug potency by effect within a category when used as monotherapy
(****high, *low). Authors’ preference by category (5 high, 1 low). If [O,**,4] is for the whole class it follows the class, e.g. ACE inhibitors, but if it
is for a specific drug within a class it follows each drug, e.g. diuretics. Note potencies are for category that drug is listed in and authors’
preference is for category effect and some drugs appear in more than one category because they have polypharmacy effects. For example,
pimobendan is a strong positive inotrope and is our first preference in this category as an oral drug and although it is an afterload reducer
and this is a desirable property, if we need to select an afterload reducer we would pick amlodipine empirically as it is more potent but we
would still use pimobendan for its combination of effects in canine CHF.
Note: Most common SVA = atrial fibrillation.
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