Antarrhythmics

Question 1

All antiarrhythmics can precipitate _______

Answer 1

Lethal arrhythmia

Question 2

All class I drugs do what

Answer 2

Block sodium channels

Question 3

Which sodium channels do Class IA drugs block?

Effect on refractory period and action potential?

Answer 3

Open and activated Na+ channels

AP lengthened
RP lengthened

Question 4

Which sodium channels are blocked by Class IB Drugs?

Effect on action potential and refractory period?

Answer 4

Inactivated Na+ channels

Shorten AP

Shorten RP

Question 5

Which sodium channels are blocked by class I C drugs?

Effect on refractory period and Action potentiak?>

Answer 5

ALL sodium channels

No effect on AP

No effect on RP

Question 6

What are the 2 class IA drugs

Answer 6

Quinidine

Procainamide

Question 7

Which drug is class IB drug

Answer 7

Lidocaine

Question 8

What drug is class I C

Answer 8

Flecainide

Question 9

What is the MOA of Class II drugs

Answer 9

Reduce adrenergic activity on the heart

Question 10

Which drugs are class II

Answer 10

Beta blockers

Question 11

What is the MOA of Class III drugs?

Effect on action potential?

Effect on refractory period?

Answer 11

Blocks K+ channels

AP lengthened**

No effect on RP

Question 12

What drugs are Class III

Answer 12

Amiodarone

Sotalol

Question 13

What is the MOA of Class IV drugs

Answer 13

Calcium channel blockers: decrease HR and contractility

Question 14

Which drugs are Class IV

Answer 14

Verapamil

Diltiazem

(Non-dihydropyridine CCBs)

Question 15

How do you treat Torsades

Answer 15

Magnesium

Question 16

What drug is the “broad spectrum” antiarrhtyhmic because it treats supraventricular and ventricular arrhythmias

Answer 16

Quinidine

Question 17

What are the adverse effects of quinidine

Answer 17

Cardiac toxicity: SA block, AV block, ventricular arrhythmia

Blocks alpha receptors= hypotension and reflex tachycardia

Paradoxical tachycardia

Torsade de pointes

Diarrhea** big deal!

Cinchonism: hearing loss, angioedema vertigo, tinnitus, etc

Question 18

Any drug that _______________ has the potential to cause Torsade de pointes

Answer 18

Prolongs QT interval

Question 19

What is the adverse effect of Procainamide?

Answer 19

Drug induced Lupus in slow acetylators

Question 20

What is the MOA of lidocaine

Answer 20

Blocks ~inactivated~ Na+ channels

=preferentially affects damaged tissue= more receptors are inactivated

Question 21

What is the DOC for acute VENTRICULAR arrhythmias?

Answer 21

Lidocaine****

If you see VENTRICULAR arrhythmia on a question the answer is lidocaine

Question 22

What is the main adverse effect of lidocaine

Answer 22

Seizures/convulsions

Question 23

What is the MOA of Flecainide?

Answer 23

Strongly blocks all Na+ channels

No effect on ERP due to indiscriminate binding to ALL Na channels

Question 24

Which antiarrhytmic is a last ditch effort drug

Answer 24

Flecainide

Question 25

What is the adverse effect of flecainide

Answer 25

STRONG pro-arrhythmic effect

Question 26

What is Esmolol used for?

Answer 26

Emergency treatment (Short half life, IV only)

Question 27

Are acebutolol and esmolol non-specific B blockers?

Answer 27

No, B1 only

Question 28

What is the MOA of amiodarone

Answer 28

Blocks K+ channels Extends length of AP*****!!! Other mechanisms: Blocks Na+ channels (Class I) B blocker (Class II) CCB effect (Class IV) Alpha blocker

Question 29

What kind of arrhythmias can be treated with Amiodarone

Answer 29

Supraventricular Ventricular

Question 30

What is the DOC for supraventricular arrhythmias

Answer 30

Amiodarone

Question 31

Amiodarone prolongs QT. Can it cause torsades?

Answer 31

No!!****

Question 32

What drug can cause pulmonary fibrosis after a long term high dose?

Answer 32

Amiodarone***** This is probably a test q (Ground glass appearance)

Question 33

What are the adverse effects of amiodarone

Answer 33

Pulmonary fibrosis Turns cornea yellowish-brown and skin turns grayish blue Thyroid dysfunction (iodine derivative)

Question 34

What is the MOA of Sotalol

Answer 34

K+ blocker= prolongs AP Non selective Beta blocker**

Question 35

What kind of arrhythmia can be treated with Sotalol

Answer 35

Ventricular Supraventricular

Question 36

Who can NOT be given Sotalol

Answer 36

Asthmatics!**** NON SPECIFIC B-BLOCKER WITH K+ CHANNEL BLOCKING PROPERTIES

Question 37

What are the adverse effects of Sotalol

Answer 37

Torsades B-receptor blockade= not for asthmatics

Question 38

What kind of arrhythmias are treated with verapamil and diltiazem

Answer 38

Reentrant SUPRAventricular tachycardia ******* PSVT AFib and flutter

Question 39

What part of the heart is affected the most by CCBs

Answer 39

atria!! | NOT THE VENTRICLES

Question 40

What is the order of treatment for Acute PSVT

Answer 40

1. Adenosine 2. Esmolol 3. CCBs (via IV!)

Question 41

What is the order of treatment for chronic PSVT?

Answer 41

B-Blockers (oral) CCBs (oral)

Question 42

What is the DOC for acute PSVT and WPW syndromes

Answer 42

Adenosine

Question 43

What is the MOA of adenosine

Answer 43

Enhanced K+ conductance and inhibition of Calcium influx= Hyperpolarized everything and resets the heart!*

Question 44

What is the half life of adenosine

Answer 44

10 seconds | Stops the heart for 10 seconds!

Question 45

Adenosine is only effective for _________arrhythmias

Answer 45

Reentry | Most PSVTs are

Question 46

What is the MOA of magnesium

Answer 46

Unknown

Question 47

What is IV magnesium used for

Answer 47

Torsade de Pointes***** Digitalis induced arrhythmias

Question 48

Anything that increases action potential duration will also increase ________

Answer 48

QT interval

Question 49

Anything that increases QT interval has a chance of causing ____________ except for _________

Answer 49

Torsade de pointes Amiodarone

Question 50

Route of administration for lidocaine, adenosine and mangneisum?

Answer 50

IV only.... used only in acute therapy

Question 51

The stronger or broader a drug is in its effects, the more potential for causing ____________

Answer 51

Arrhythmias | Lidocaine vs flecainide for example

Question 52

Class IV can only be used for (ventricular/supraventricular)

Answer 52

Supraventricular

Question 53

Class 1B can only be used for (supraventricular/ventricular)

Answer 53

Ventricular

Question 54

Why are Class IV only effective in supraventricular arrhythmias

Answer 54

Because thats where Calcium is important for rate

Question 55

Why does class 1B (Lidocaine) only work for ventricular arrhythmias?

Answer 55

Thats the only place where there is a plateau phase where the “window” current is functioning