Drugs For Cardiac Arrhythmias (Konorev)

Question 1

What are the 1B Na channel blocking drugs?

Answer 1

Lidocaine

Mexiletine

Question 2

Which cell types have a fast AP?

Answer 2

Ventricular contractile cardiomyocytes
Atrial cardiomyocytes
Purkinje fibers

Question 3

Which cell types have a slow (pacemaker) AP?

Answer 3

SA node cells

AV node cells

Question 4

What are the 1C Na channel blocking drugs?

Answer 4

Flecainide

Propafenone

Question 5

What are the class 2 antiarrhythmic drugs?

Answer 5

Beta blockers

Esmolol and propanolol

Question 6

What are class 3 antiarrhythmic drugs?

Answer 6

K channel blocking drugs
Amiodarone
Dronedarone
Sorta lol
Dofetilide
Ibutilide

Question 7

What are class 4 antiarrhythmic drugs?

Answer 7

Cardioactive Ca channel blockers

Verapamil and Diltiazem

Question 8

Class 1A drugs preferentially bind to __ channels

Answer 8

Open (activated) Na

Question 9

Class 1A drugs have what effects on the following:

• K channels: ___
• AP duration: ___
• QRS and QT intervals: ___

Answer 9

Block

Prolong

Prolong

Question 10

This 1a drug is used to tx sustained V tach, directly depresses the activities of SA and AV nodes, and possesses antimuscarinic activity

Answer 10

Procainamide

Question 11

What are adverse effects of Procainamide?

Answer 11

Cardiac –> QT prolongation, induce Torsade de pointes and syncope

Extracardiac –> lupus syndrome, nausea, diarrhea, and agranulocytosis

Question 12

This 1a drug is a natural alkaloid from Cinchona bark that is used occasionally for restoring rhythm in A flutter/fib pts with normal (but arrhythmic) hearts

Answer 12

Quinidine

Question 13

What are adverse effects of quinidine?

Answer 13

Cardiac –> QT prolongation, induce Torsades

Extracardiac –> GI side effects, headache, dizziness, tinnitus, thrombocytopenia, hepatitis, fever

Question 14

This 1a drug is used for tx of recurrent V Tac

Answer 14

Disopyramide

Question 15

What are adverse effects of Disopyramide?

Answer 15

Cardiac –> QT prolongation, induce torsades, negative inotropic effect

Extracardiac –> atropine-like symptoms

Question 16

Class 1B drugs bind to ___ channels

Answer 16

Inactivated Na , preferentially bind to depolarized cells

Question 17

This 1B drug blocks inactivated Na channels-selectively blocks conduction in depolarized tissue, making damaged tissue completely “electrically silent”. It is used in mono- and polymorphic V Tac

Answer 17

Lidocaine: extensive 1st pass metabolism and only by IV route

This is the least toxic of all Class I drugs

Question 18

__ is an orally active 1B drug used for ventricular arrhythmias, to relieve chronic pain (esp pain d/t diabetic neuropathy and nerve injury)

Answer 18

Mexiletine

Adverse effects: tremor, blurred vision, nausea, lethargy

Question 19

Class 1C drugs block Na channels to slow impulse conduction and preferentially bind to __ Na channels

Answer 19

Open (activated)

They also block certain K channels

Question 20

What do 1C drugs do to the QRS complex?

Answer 20

Prolong QRS

Question 21

This 1C drug blocks Na and K channels and has no antimuscarinic effects. It is used to tx pts with normal hearts, supraventricular arrhythmias including AF, paroxysmal SVT (AVNRT, AVRT).

Answer 21

Flecainide

Question 22

This 1C drug possesses weak B-blocking activity and used to prevent paroxysmal AF and SVT in pts without structural disease and also used in sustained ventricular arrhythmias

Answer 22

Propafenone

Question 23

What are some adverse effects of Propafenone and what should you no combine with?

Answer 23

Exacerbates ventricular arrhythmias
Metallic taste
Constipation

Do NOT combine with CYP2D6 and CYP3A4 inhibitors as risk of proarrhythmia may be increased

Question 24

What effects do class 2 drugs have on the following:

• SA node: ___
• AV node: ___
• Ventricular myocardium: ___

Answer 24

SA node: decrease HR (Increase RR interval)
AV node: decrease AV conductance (Increase PR interval)
Ventricular myocardium: decrease Ca overload, prevent delayed after-depolarizations

Question 25

What are clinical indications for Propanolol (class 2)?

Answer 25

Arrhythmias associated with stress Re-entrant arrhythmias that involve the AV node A fib and flutter Arrhythmias associated with MI

Question 26

This class 2 drug is a selective B1 blocker with a short half life (10 min) on continuous IV fusion

Answer 26

Esmolol

Question 27

What effects do Class 3 drugs have on the following: - AP: ___ - QT interval: ___ - Refractory period:___

Answer 27

Prolong AP duration Prolong QT interval Prolong refractory period

Question 28

This class 3 drug blocks K and inactivated Na channels, prolongs QT interval and APD uniformly over wide range of HR's. It possesses adrenolytic activity, has Ca channel blocking activities, cuases bradycardia and slows AV conduction. It can also cause peripheral vasodilation and is used to Tx ventricular arrhythmias

Answer 28

Amiodarone

Question 29

Amiodarone is metabolized by ___

Answer 29

CYP3A4 1/2 life affected by drugs that inhibit CYP3A4 (Cimetidine) or induce it (Rifampin)

Question 30

What are some adverse effects of Amiodarone?

Answer 30

Cardiac --> AV block and bradycardia Extracardiac --> fatal pulm fibrosis, hepatitis, photodermatitis, depositis of drug in cornea and other eye tissues, blocks peripheral conversion of thyroxine to triiodothyronine

Question 31

This class 3 drug blocks multiple K channels, blocks Na current, blocks L-type Ca current, and has stronger antiadrenergic effects than Amiodarone

Answer 31

Dronedarone

Question 32

What is the Black box warning for Dronedarone?

Answer 32

Increases risk of mortality in pts with decompensated HF (Class IV) and in pts with a recent decompensation of HF requiring hospitalization

Question 33

This drug is a class 2 (non-selective B blocker) and class 3 agent (prolongs APD). It is used to tx life-threatening ventricular arrhythmias and maintenance of sinus rhyth in pts with A fib.

Answer 33

Sorta lol

Question 34

What are adverse effects of Sotalol?

Answer 34

Depress cardiac function | Provoke Torsades

Question 35

This class 3 drug specifically blocks rapid component of delayed rectifier K current. It has a very narrow therapeutic window and used to convert AF to the sinus rhythm and maintain sinus rhythm after cardioversion.

Answer 35

Dofetilide

Question 36

What are adverse effects of Dofetilide?

Answer 36

QT prolongation and increased risk of ventricular arrhythmias

Question 37

What effects do Class 4 drugs have on the following: - Slope of phase 0 depolarization: ___ - SA node depolarization: ___ - AV node conduction time: ___ - AP duration and refractory period in AV node: __

Answer 37

Decrease slope of phase 0 depolarization Slow SA node depol., causing bradycardia Prolong AV node conduction time Prolong AP duration and refractory period in AV node

Question 38

What are clinical uses of Diltiazem?

Answer 38

Prevention of paroxysmal SVT | Rate control in A fib and A flutter

Question 39

What are adverse effects of class 4 drugs?

Answer 39

Cardiac --> negative inotropy, AV block, SA node arrest, bradyarrhythmias, hypotension Extracardiac--> constipation (Verapamil)

Question 40

This drug activates K current and inhibits Ca funny currents, causing marked hyperpolarization and suppression of APs in pacemaker cells. It inhibits AV conduction and increases nodal refractory period. It is used clinically to convert sinus rhythm in paroxysmal SVT

Answer 40

Adenosine

Question 41

What are adverse effects of adenosine?

Answer 41

``` SOB Bronchoconstriction Chest burning AV block Hypotension ```

Question 42

Which antiarrhythmic drug classes can cause long QT syndrome and torsade de pointes arrhythmias?

Answer 42

Class 1a and 3

Question 43

What are the 1A Na channel blocking drugs?

Answer 43

Quinidine Procainamide Disopyramide