ANTIARRYTHMIC DRUGS

Question 1

Electrical behaviour classification

Answer 1

Electrical behaviour (less clinical):
Class I: Membrane stabilising drugs (Lidocaine, Flecainide)
Class II: Beta-blockers
Class III: Amiodarone, sotalol (also class II)
Class IV: RL CCB (verapamil, dittiazem - NOT “-pines”)

Question 2

List the drugs that act
ONLY on supra-ventricular arrhythmia?

Answer 2

• Adenosine
• Digoxin
• Verapamil (and diltiazem -
  Usually Unlicensed)

Question 3

List the drugs that act
ONLY on ventricular arrhythmia?

Answer 3

Lidocaine

Question 4

List the drugs that act on BOTH supra-ventricular AND ventricular arrhythmia?

Answer 4

• BB
• F PADS
  (Special order: Mexiletine, Procainamide)

Question 5

Digoxin - indication

Answer 5

• AF
• sedentary
• only effective at rest

Question 6

What is the dose of digoxin for Atrial fibrillation in comparison to heart failure?

Answer 6

The daily dose in AF is double then Heart failure
Max dose 250mcg OD for AF and 125mcg for HF

Question 7

Which calcium channel blockers are used in
supraventricular arrhythmias?

Answer 7

• Verapamil
• Diltiazem (Unlicensed)
  NOT Dihydropyridines (e.g.
  Amlodipine)

Question 8

What class are the rate-limiting calcium channel blockers?

Answer 8

Class 4

Question 9

Verapamil - MOA

Answer 9

Verapamil has a highly negative inotropic effect
Verapamil also:
- Reduces cardiac output
- Slows heart rate
- Impairs atrioventricular conduction

Question 10

What is verapamil’s dose in AF compared with hypertension?

Answer 10

The dose of hypertension is double then AF
Or other words.. dose in AF is half that in hypertension

Question 11

Verapamil - CI

Answer 11

• HF
• AF or Atrial flutter associated with accessory conducting pathway (e.g. wolf-white
  Parkinson syndrome)

Question 12

Verapamil - interactions

Answer 12

BB

Question 13

Verapamil - SE

Answer 13

• Constipation
• Flushing, headache, syncope, palps
• oedema common in dihydropyridines, but uncommon with verapamil

Question 14

Can diltiazem be taken with Beta-blockers?

Answer 14

Because of its less negative inotropic and myocardial depression effects than verapamil, it can.
But use with caution!

Question 15

Which IV beta-blockers can be used for rapid control of ventricular rate?

Answer 15

• Propranolol
• Esmolol

Question 16

What class are beta-blockers?

Answer 16

2

Question 17

Adenosine - indication

Answer 17

Paroxysmal SV arrythmia

Question 18

Adenosine - CI

Answer 18

• Asthma
• QT interval prolongation

Question 19

Adenosine - SEs

Answer 19

• angina
• bronchospasms
• arrhythmias

Question 20

What class is Disopyramide?

Answer 20

1

Question 21

What are the uses of Disopyramide?

Answer 21

To control arrhythmias (ventricular and supraventricular), specifically after a Myocardial infarction (MI)

Question 22

Which side-effect of Oral Disopyramide should you be aware of?

Answer 22

• antimuscarinic side-effects
• This may limit its use in patients with glaucoma and benign prostatic hyperplasia (BPH)

Question 23

What class is flecainide?

Answer 23

1

Question 24

What are the
contraindications for Flecainide?

Answer 24

Structural or ischaemic heart disease:
- Bundle branch block
- left ventricular hypertrophy
- Heart failure

Question 25

What are the side effects of flecainide?

Answer 25

• Arrhythmia
• Dizziness
• Dyspnea
• Oedema

Question 26

Why is propafenone contraindicated in severe obstructive airway disease?

Answer 26

Due to its weak beta-blocking activity
But it can be used with caution in mild to moderate airway disease

Question 27

What class is propafenone?

Answer 27

1

Question 28

What class is lidocaine?

Answer 28

1

Question 29

When is Lidocaine indicated?

Answer 29

IV:
- ventricular tachycardia in haemodynamically stable patients
- ventricular fibrillation
- pulseless ventricular tachycardia in cardiac arrest refractory to defibrillation