Antiarrhythmic drugs

Question 1

Procainamide MOA

Answer 1

Class 1a

• Na+ channel blocker=primary
• K+ channel blocker=secondary

Question 2

Procainamide effects

Answer 2

Slows conduction velocity and pacemaker rate

Question 3

Procainamide clinical applications

Answer 3

Atrial and ventricular arrhythmias

Question 4

Procainamide side effects

Answer 4

1. Torsades de pointes in pt’s with renal failure
2. Hypotension
3. Long term: Reversible lupus-related sx’s

Question 5

Lidocaine MOA

Answer 5

Class 1b

• Weak Na+ channel blocker
• Minimal effect on normal tissue

Question 6

Lidocaine Clinical applications

Answer 6

Ventricular arrhythmias (post-MI)

Question 7

Lidocaine toxicity

Answer 7

Neurologic sx’s: CNS sedation or excitation

Question 8

Who do we want to reduce Lidocaine dose in?

Answer 8

1. HF pt’s

2. Liver dz pt’s

Question 9

Flecainide MOA

Answer 9

Group 1c

-Strong Na+ channel blocker

Question 10

Flecainide effects

Answer 10

No change in AP duration

Question 11

Flecainide Clinical application

Answer 11

Treat supra ventricular arrhythmias (SVT) in pt’s with a NORMAL HEART

Question 12

Who do we want to avoid giving Flecainide to?

Answer 12

Ischemic heart disease pt’s (post-MI)

Pro-arrhythmic

Question 13

Class II drugs

Answer 13

Beta-Blockers

Question 14

Beta-Blockers effects

Answer 14

Prolongation of AP duration

1. Slows SA node automaticity
2. Slows AV nodal conduction velocity

Question 15

Beta-Blocker Clinical applications

Answer 15

1. Atrial arrhythmias

2. Prevention of recurrent infarction an sudden death

Question 16

Beta-Blocker toxicity

Answer 16

1. Asthma
2. AV block
3. Acute HF

Question 17

Class III drug

Answer 17

1. Amiodarone

2. Dofetilide

Question 18

Amiodarone MOA

Answer 18

Blocks K+ channels

Question 19

Amiodarone effects

Answer 19

1. Prolongs QT (repolarization)

2. Prolongs AP= Prolongs effective refractory period!!!

Question 20

Amiodarone clinical applications

Answer 20

1. Serious Ventricular arrhythmias

2. SVT

Question 21

Amiodarone toxicity

Answer 21

1. Thyroid dysfunction: Hyper-hypothyroidsim
2. Pulmonary fibrosis
3. Optic neuritis

Question 22

Amiodarone drug interaction

Answer 22

Many, based on CYP metabolism

Question 23

What is considered the blue/ash man drug? Why? How do you protect against this?

Answer 23

1. Drug: Amiodarone
2. Photosensitivity: blue/gray skin
3. WEAR SUNBLOCK

Question 24

What drug has to be initiated in the hospital? Why?

Answer 24

Dofetilide

–>Torsades de point toxicity

Question 25

Class IV drugs

Answer 25

Calcium channel blockers:

1. Verapamil
2. Diltiazem

Question 26

Effects of CCB

Answer 26

1. Slows AV node conduction

2. Slows SA node

Question 27

Verapamil clinical application

Answer 27

1. AV nodal arrhythmias-especially in prophylaxis

Question 28

Diltiazem clinical applications

Answer 28

Rate control in a-fib

Question 29

CCB side effects

Answer 29

1. Constipation

2. Hypotension

Question 30

Magnesium clinical application

Answer 30

1. Torsades de pointes

2. Digitalis induced arrhythmias

Question 31

Magnesium toxicity

Answer 31

Muscle weakness with overdose

Question 32

What does Magnesium oppose?

Answer 32

Calcium

Question 33

What ion is critical to functionality of Ca2+ channels and Na+/K+ ATPase pump?

Answer 33

Magnesium

Question 34

Potassium toxicity?

Answer 34

1. Reentrant arrhythmia

2. Fibrillation or arrest in overdose

Question 35

Adenosine MOA

Answer 35

Increases K+ efflux of SA and AV node= hypwrpolarazing cell and decreasing frequency of cellular activation

Question 36

Adenosine clinical application

Answer 36

Paroxysmal SVT

Question 37

Adenosine toxicities

Answer 37

1. Flushing
2. Chest tightness-“heart will stop”
3. Dizziness/Hypotension
4. Dyspnea