Cardiovascular Drugs 1

Question 1

Cardiovascular System

Answer 1

• Comprised of heart and blood vessels
• Its main function is to transport to and from body tissues
• Drugs used to treat the CV system are potent and can have serious side effects

Question 2

Normal cardiac cycle

Answer 2

o Atria contract pushing blood into ventricles

o Ventricles contract pushing blood out to body tissues

Question 3

Cardiac muscle contraction is controlled by:

Answer 3

• is controlled by the movement of mineral ions in and out of cardiac muscle cells
o movement of ions across cell membrane leads to depolarization
o depolarization of cardiac muscle cells causes contraction
o waves of depolarization always begin at the sinoatrial (SA) node, then progressively spread

Question 4

waves of depolarization always begin at the sinoatrial (SA) node, then progressively spread to

Answer 4

 atria
 atrioventricular (AV) node
 Bundle of Hiss
 ventricles

Question 5

Effect of autonomic nervous system on CV function

Answer 5

Sympathetic n.s.-> inc. HR and contractility
-> vasoconstriction
Parasympathetic n.s.-> dec. HR

Question 6

Arrhythmia

Answer 6

an abnormal pattern of electrical activity in the heart

Question 7

Antiarrhythmic Drugs

Answer 7

• Usually caused by a group of abnormal cells -> depolarize on their own, not in conjunction w/ the SA node
• Antiarrhythmics prevent autodepolarization of these cells by slowing down the movement of ions through their cell membranes

Question 8

Sodium influx inhibitors

Answer 8

• lidocaine, quinidine, procainamide

o inhibit movement of sodium ions across cell membranes

Question 9

Licocaine

Answer 9

should be given IV
large doses may cause sedation, ataxia, drowsiness
cardiovascular shock and seizures occur w/ overdose

Question 10

Procainamide and quinidine

Answer 10

• both available in oral form
• procainamide can be given IM, IV
• quinidine can
  
  • -cause vomiting, diarrhea, anorexia
  • -increase digoxin plasma levels

Question 11

Calcium channel blockers

Answer 11

diltiazem, verapamil

• block movement of calcium across channels in the cell membrane
• may decrease heart contractility

Question 12

Beta blockers

Answer 12

propanolol

-blocks sympathetic n.s. receptors, dec. contraction rate of the heart

Question 13

Adverse effects of Beta blockers

Answer 13

decreases contractility
bronconstriction
abnormally slow HR
lose effectiveness over time

Question 14

Positive Inotropic Drugs

Answer 14

• Increase the strength of contraction of the heart

* Used when heart muscle is too weak to pump (e.g. congestive hear failure)

Question 15

Pimobendan

Answer 15

o Newest inotropic drug that is also a vasodilator
o Increases intracellular calcium sensitivity
o Used to treat CHF due to dilated cardiomyopathy or valve insufficiency
o Can be safely used in conjunction with other cardiac drugs

Question 16

Digoxin

Answer 16

-Older inotropic drug
-makes more calcium available inside cardiac muscle cells to improve contraction
-enhances the parasympathetic n.s. effect on the heart
-narrow therapeutic range
(Adverse effects include anorexia, vomiting, diarrhea, arrhythmia)

Question 17

Vasodilators

Answer 17

o Vasoconstriction is the body’s response to low blood pressure due to a failing heart
Makes it harder for the failing heart to pump blood
o Vasodilators prevent vasoconstriction from occurring

Question 18

Enalapril (Enacard), Benazepril, Captopril

Answer 18

block formation of angiotensin II which is responsible for vasoconstriction and sodium retention

Question 19

Hydralazine

Answer 19

causes direct relaxation of vascular smooth muscle

Question 20

Prazosin

Answer 20

blocks vasoconstriction caused by the sympathetic n.s.

Question 21

Nitroglycerin

Answer 21

applied topically, caused dilation of veins

Question 22

Diuretics

Answer 22

• Increase urine formation to promote water loss from the body
• decreases the volume of blood the heart has to pump

Question 23

Furosemide (Lasix)

Answer 23

• prevents reabsorption of sodium from the renal tubule

- prolonged use can lead to abnormally low potassium levels

Question 24

Thiazide diuretics (chlorthiazide

Answer 24

• prevents reabsorption of sodium from the renal tubule
• prolonged use can lead to abnormally low potassium levels
• less potent than furosemide
• loses effectiveness w/ long-term use

Question 25

Mannitol

Answer 25

• small sugar molecule freely filtered by the kidney

- creates an osmotic force that pulls water into the renal tubule

Question 26

Spironolactone

Answer 26

Aldosterone antagonist used for congestive heart failure, especially if hypokalemia is a concern

Question 27

Aspirin

Answer 27

• Prevents platelet aggregation

- Reduces chance of clot formation

Question 28

Bronchodilators

Answer 28

aminophylline, theophylline

-cause vasodilation of blood vessel near the heart by inc. blood oxygen content

Question 29

Sedatives and Tranquilizers

Answer 29

decrease sympathetic nervous system stimulation by calming animal down