CV Drugs 1

Question 1

what is the MOA of methylxanthines?

Answer 1

Phosphodiesterase inhibition > inc. amounts of cAMP > inc. release of ENDOGENOUS epinephrine

Question 2

T/F: methylxanthines are cardiac stimulants

Answer 2

TRUE, include aminophylline and theophylline

Question 3

what is the main effect of methylxanthines?

Answer 3

bronchodilation! direct relaxation of smooth m. in bronchi and pulmonary vasculature

Question 4

what type of arrhythmia are methylxanthines occasionally used for?

Answer 4

bradyarrhythmias i.e. AV block

Question 5

in what situation are methylxanthines contraindicated?

Answer 5

patients with severe cardiac disease or hypertensions (risk tachycardia, worsen tachyarrhythmias)

Question 6

T/F: methylxanthines induce diuresis making them cardiac diuretics

Answer 6

TRUE

Question 7

what is the major difference between aminophylline and theophylline?

Answer 7

aminophylline is the parenteral form of theophylline

Question 8

what is the most commonly used catecholamine for CHF due to myocardial failure?

Answer 8

dobutamine = B-1 agonist

Question 9

what might occur if you use methylxanthines with a severely hypoxic patient?

Answer 9

you may worsen V/Q mismatch

Question 10

what is a cardiac stimulant that is also one of the drugs of choice for treatment of calcium channel blocker toxicity?

Answer 10

glucagon

Question 11

what cardiac stimulant is one of the drugs of choice for emergency treatment of hyperkalemia?

Answer 11

calcium salts

Question 12

what categories of drugs would you use for pharmacologic therapy of CHF?

Answer 12

• • inotropes
• vasodilators
• inodilators
• diuretics
• beta-blockers

Question 13

what adjunctive therapy can you do in addition to pharmacologic therapy for CHF?

Answer 13

• sodium-restricted diet
• exercise restriction
• oxygen therapy

Question 14

T/F: digoxin is used extra-label and is a cardiac stimulant

Answer 14

FALSE, digoxin is a positive inotropic drug

Question 15

what kind of metabolism does digoxin undergo?

Answer 15

enterohepatic recirculation

Question 16

T/F: digoxin is excreted mainly in renal in cats and renal and hepatic in dogs and horses

Answer 16

FALSE, opposite

Question 17

what sort of renal effect do you see with the use of digoxin?

Answer 17

= cardiac diuretic, secondary to increased CO

Question 18

T/F: acute use in digoxin will result in HYPERkalemia while chronic use will result in HYPOkalemia

Answer 18

TRUE

Question 19

what is the number one adverse effect of digoxin?

Answer 19

GI signs ( irritation, vomiting, nausea, anorexia, diarrhea)

Question 20

what type of digoxin-induced arrythmias are possible?

Answer 20

TACHYarrhythmias

Question 21

what is the specific antidote for digoxin toxicity?

Answer 21

digoxin immune Fab (Digibind)

Question 22

what drug can you use if you have digoxin toxicity and want to decrease enterohepatic recirculation?

Answer 22

cholestyramine

Question 23

what are the two clinical uses for digoxin?

Answer 23

CHF and atrial fibrillation or flutter

Question 24

besides serving as a positive inotrope what other major effect does pimobendan have?

Answer 24

vasodilator! = PDE III inhibitor which results in arterial and venous dilation (reduced preload and afterload)

Question 25

what is the route of administration for pimobendan?

Answer 25

ORAL, aborption is rapid

Question 26

what are the two major contraindications for the use of pimobendan?

Answer 26

HCM (cats) and aortic stenosis

Question 27

what is the drug of choice for the treatment of CHF in dogs?

Answer 27

pimobendan, improves quality and length of life in dogs w/ DCM and MMVD

Question 28

which of the following is not a clinical effect associated w/ theophylline?

a. tachycardia
b. bronchodilation
c. bradycardia
d. increased urination

Answer 28

c. bradycardia

Question 29

which of the following best describes the MOA of pimobendan?

a. inodilator through myocardial sensitization to calcium & PDE III inhibition
b. inodilator through increases intracellular calcium available for exchange w/ sodium
c. positive inotrope through beta-1 receptor agonism
d. negative chronotrope through beta-1 receptor antagonism

Answer 29

a. inodilator through myocardial sensitization to calcium & PDE III inhibition

Question 30

which of the following drugs used concurrently w/ digoxin may increase the risk of signs of digoxin toxicity?

a. furosemide
b. spironolactone
c. pimobendan
d. none of these

Answer 30

a. furosemide (MOA is inhibition of Na/K symport)