Cardiovascular Drugs

Question 1

What is arrhythmia?

Answer 1

alteration in normal impulse pathway

Question 2

Name major cause of sudden cardiac death.

Answer 2

ventricular fibrillation

Question 3

what is cardioversion?

Answer 3

global depolarization of heart to reset heart beat. Can be achieved via defibrillation

automatic defibrillators can be implanted

Question 4

radiofrequency ablation accomplishes what?

Answer 4

the removal of ectopic foci - points that induce abnormal electrical signals in the heart

Question 5

Do antiarrhhythmic drugs affect ectopic or normal foci more?

Answer 5

ectopic

Question 6

What class of drug is quinidine?

Treats which arrhythmias?

range of effectiveness?

SEs?

Answer 6

class Ia sodium channel blocker

effective in treating all arrhythmias

depresses all muscle function

SEs:

• GI upset
• Nausea
• Anorexia
• CNS: tinnitus, altered color vision

Question 7

Which class of drug is Procainamide?

Treats which arrhythmias?

analog of what?

Does it enter CNS?

Notable SE?

Answer 7

class: Ia sodium channel blocker

Treats: all arrhythmia

analog of Procaine

DOES NOT enter CNS

SE: in slow acetylators, lupus-like syndrome

Question 8

Disopyramide is what class of drug?

Effects?

used to treat which type of arrhythmias?

Answer 8

class: sodium channel blocker

strong anti-vagal effects aka anti-muscarinic effect (opposite of DUMBBELS)

treats: ventricular arrythmias

Question 9

Lidocaine is what class of drug?

Lidocaine is the DOC for what?

Does Lidocaine enter the CNS?

SEs?

Answer 9

class Ib sodium channel blocker

DOC for ventricular tacchycardia
less likely to cause arrhythmias

Yes, it does enter CNS

CNS SEs:

• tremors
• seizures

Question 10

Mexiletine is similar to what other sodium channel blocker?

Answer 10

Lidocaine and also is a class Ib sodium channel blocker

Question 11

Name the 5 sodium channel blockers used to treat arrythmias

Answer 11

Procainamide - all arrhythmias
quinidine - all arrhythmias

disopyramide - ventricular arrhythmias
lidocaine - ventricular tachycardia

mexiletine - not specified

Question 12

Name 3 beta blockers used to treat arrhythmia and additional characteristics of each.

MOA?

SEs?

Answer 12

Propanolol: also affects beta2, decreases pacemaker firing rate

Osmolol: rapid onset

Metoprolol: more selective, less beta2 effect

MOA: block beta-1 receptors in heart - effectively slows HR

SEs:
-hypotension
if beta 2 affect: asthma concerns

Question 13

What are the K+ channel blockers used?

Answer 13

atrial fibrillation

Question 14

name 3 potassium channel blockers used for atrial fibrillation and characteristics / SEs of each

Answer 14

Sotalol: beta blocker that also blocks potassium channels

Amiodarone: acts like all 4 antiarrhythmic drug classes
-most effective: DOC for cardiac arrest
-contains iodine
SEs:
-potentially fatal pulmonary fibrosis
-liver damage
-corneal deposits --> optic neuritis
-skin deposits --> blue skin coloration (iodine)
-GI upset

Dronedarone:

• analog of amiodarone
• fewer SEs, less efficacy

Question 15

Name 3 calcium channel blockers used to treat arrhythmia.

What is their effect on cardiac cells?

For which arrhythmia type are they useful?

Answer 15

Diltrazem
nifedipine
verapamil

increase refractory period

NOT useful for ventricular arrhythmia

Question 16

How does adenoside work?

What is its effect?

For what is it used?

Answer 16

binds adenosine receptor -> slows AV node

serves as coronary vasodilator

used for atrial tachycardia and disappears quickly

Question 17

how is angina treated?

Answer 17

increasing blood flow to heart or by decreasing O2 demand

nitrates - nitroglycerin (GTN)
-rapid dilation of all blood vessels

exercise - increase collateral circulation

isosorbide dinitrate - slow release nitrate formulation (oral admin b/c slow release off sets first pass of GTN)

beta blockers

calcium channel blockers

Question 18

For what is nitroglycerin used?

MOA?

Side Effects?

Answer 18

angina, life threatening hypertension

GTN -> NO -> activates guanylate cyclase -> cGMP (vasodilator)

SEs:

• hypotension
• flushing of skin
• headache

Tachyphylaxis - rapid tolerance

Question 19

How does the heart adapt to congestive heart failure?

Answer 19

heart enlarges, blood backs up at lungs -> pulmonary congestion -> decreased ability to breathe

release of EPI, NE, AngII to increase HR, BP, vasoconstriction

increase blood vol via AngII -> increase in Na+ retention and activation of of Na+ / K+ exchanger

Question 20

Ionotropic agents are used to treat what?

What is the logic behind their use?

Examples include?

Answer 20

tx for cardiac insufficiency

ions such as Ca2+ are essential to cardiac contraction. If you increase Ca2+, you increase contractility and can compensate for cardiac insufficiency.

examples:

the cardiac glycoside digoxin

dobutamine: strong ionotropic effect: increased force of contraction

Question 21

Explain out loud to yourself in front of a bunch of people with your hands above your head while hyperventilating how digoxin works.

Toxicities?

Answer 21

cardiac glycosides inhibit Na+ - K+ ATPase -> Na+ remains high in the cell. This inhibits Na+ / Ca2+ exchanger ultimately preventing the loss of Ca2+. Calcium inside the membrane remains high = greater contractility

Toxicities:
-heart: arrhythmia (increased vagal tone
-CNS: yellow / green vision, hallucinations, CTZ = nausea and vomiting (monarchs)
effect of digoxin is greatly increased by hypokalemia

Question 22

What is ultimately the best tx for congestive heart failure?

Name the drugs!

Answer 22

any agent that inhibits the body’s attempt to compensate:

• beta / alpha blockers
• ACE inhibitors
• diuretics
• vasodilators

Question 23

Name the 3 oral drugs for erectile dysfuntion

MOA?

Should not be taken with?

SEs?

Metabolized by?

Answer 23

sildenafil
vardenafil
tadalafil

inhibit type 5 cGMP phosphodiesterase -> increase in cGMP -> vasodilation in arteries of corpus cavernosum

Should NOT be taken with alpha1 blockers or nitrates (too much dilation doeee)

SEs:

• slight BP decrease
• blue-green vision
• NAION - retinal damage from cGMP PDE inhibitors
• stroke
• myocardial infarction

metabolized by P450

Question 24

Name an injectable PGE1 used to treat erectile dysfuntion

Answer 24

alprostadil