ANTIARRYTHMIC DRUGS Flashcards
Electrical behaviour classification
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”)
List the drugs that act
ONLY on supra-ventricular arrhythmia?
- Adenosine
- Digoxin
- Verapamil (and diltiazem -
Usually Unlicensed)
List the drugs that act
ONLY on ventricular arrhythmia?
Lidocaine
List the drugs that act on BOTH supra-ventricular AND ventricular arrhythmia?
- BB
- F PADS
(Special order: Mexiletine, Procainamide)
Digoxin - indication
- AF
- sedentary
- only effective at rest
What is the dose of digoxin for Atrial fibrillation in comparison to heart failure?
The daily dose in AF is double then Heart failure
Max dose 250mcg OD for AF and 125mcg for HF
Which calcium channel blockers are used in
supraventricular arrhythmias?
- Verapamil
- Diltiazem (Unlicensed)
NOT Dihydropyridines (e.g.
Amlodipine)
What class are the rate-limiting calcium channel blockers?
Class 4
Verapamil - MOA
Verapamil has a highly negative inotropic effect
Verapamil also:
- Reduces cardiac output
- Slows heart rate
- Impairs atrioventricular conduction
What is verapamil’s dose in AF compared with hypertension?
The dose of hypertension is double then AF
Or other words.. dose in AF is half that in hypertension
Verapamil - CI
- HF
- AF or Atrial flutter associated with accessory conducting pathway (e.g. wolf-white
Parkinson syndrome)
Verapamil - interactions
BB
Verapamil - SE
- Constipation
- Flushing, headache, syncope, palps
- oedema common in dihydropyridines, but uncommon with verapamil
Can diltiazem be taken with Beta-blockers?
Because of its less negative inotropic and myocardial depression effects than verapamil, it can.
But use with caution!
Which IV beta-blockers can be used for rapid control of ventricular rate?
- Propranolol
- Esmolol
What class are beta-blockers?
2
Adenosine - indication
Paroxysmal SV arrythmia
Adenosine - CI
- Asthma
- QT interval prolongation
Adenosine - SEs
- angina
- bronchospasms
- arrhythmias
What class is Disopyramide?
1
What are the uses of Disopyramide?
To control arrhythmias (ventricular and supraventricular), specifically after a Myocardial infarction (MI)
Which side-effect of Oral Disopyramide should you be aware of?
- antimuscarinic side-effects
- This may limit its use in patients with glaucoma and benign prostatic hyperplasia (BPH)
What class is flecainide?
1
What are the
contraindications for Flecainide?
Structural or ischaemic heart disease:
- Bundle branch block
- left ventricular hypertrophy
- Heart failure
What are the side effects of flecainide?
- Arrhythmia
- Dizziness
- Dyspnea
- Oedema
Why is propafenone contraindicated in severe obstructive airway disease?
Due to its weak beta-blocking activity
But it can be used with caution in mild to moderate airway disease
What class is propafenone?
1
What class is lidocaine?
1
When is Lidocaine indicated?
IV:
- ventricular tachycardia in haemodynamically stable patients
- ventricular fibrillation
- pulseless ventricular tachycardia in cardiac arrest refractory to defibrillation
