Ch.22: Inotropes (Swift) Flashcards Preview

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Flashcards in Ch.22: Inotropes (Swift) Deck (11):
1

inotropy =

contraction

2

how do inotropic drugs increase contractility?

increase Ca available to increase interaction of actin/myosin

3

cost of positive inotropes

-inc. myocardial O2 consumption
-myocardial ischemia
-maliganat arrhythmias

4

4 classes of inotropes

1) cardiac glycosides
2) beta-adrenergic agonists
3) phosphodiesterase inhibitors
4) Ca sensitizing agents

5

digoxin is what class of inotrope?

cardiac glycoside

6

MOA of cardiac glycosides*

-inhib. Na/K ATPase pump --> inc. intracellular Na, which exchanges for Ca --> increased contractility
-DELAYS conduction of SA/AV nodes

7

cardiac glycosides are used in patients with:***

-systolic myocardial (pump) failure (i.e. severe valvular dz, DCM)
-atrial fib

8

digoxin is dosed based on**

LEAN body weight. Be careful when dosing in fat/edema dogs

9

where is digozin excreted?**

kidneys. be careful when using in D/C with renal disease!!

10

digoxin therapeutic window

narrow. Overdose results in cardiac toxicity (tachy/bradyarrhythmias), CNS signs (i.e. CTZ stim. --> vomiting), and GI signs (v/d/nausea)

11

contraindications of digoxin use

-renal insufficiency, azotemia
-electrolyte disturbances, esp. hypokalemia, since K and digoxin compete for same binding sites**