Amiodarone

Question 1

Amiodarone - Type

Answer 1

Potent anti-arrhythmic agent

Question 2

Amiodarone - Presentation

Answer 2

150mg in 3ml

Question 3

Amiodarone - Actions (7)

Answer 3

Complex electrophysiological and pharmacological profile

1. Prolongs action potential duration; increases the refractoriness of all cardiac tissues
2. Blocks Na+ channels
3. Has some anti-adrenergic effects
4. Ca2+ blockade
5. Prolong QT interval - reflects global prolongation of repolarisation
6. When given IV, there is a significant effect on the AV node which causes a delay in nodal conduction
7. Also effective for accessory pathway conduction

Question 4

Amiodarone - Uses (2)

Answer 4

Effective for both supra ventricular and ventricular arrhythmias

1. To slow ventricular rate in atrial fibrillation and flutter
2. To treat VF and VT

Question 5

Amiodarone - Adverse effects (3)

Answer 5

When given IV, can cause vasodilation, negative inotropic effects and hypotension.
Occasionally may cause:
1.  Bradycardia
2. Phlebitis
3. Hot flushes/sweating

Question 6

Amiodarone - Contraindications (2)

Answer 6

1. Known hypersensitivity

2. Cross sensitivity to iodine

Question 7

Amiodarone - Doses

Answer 7

VT/VF Cardiac arrest
Adult - 300mg IV over 30-60 sec
Paediatric - 5mg/kg IV over 30-60 sec

VT, AF and AFl with cardiac output
Adult - 150mg IV via spring infuser (to 7ml = 10min)
Paediatric - 5mg/kg IV via spring infuser (to 7ml = 10min)
VT - if extremely compromised, may be given over 5/60

No repeat dose for either treatment regime

Question 8

Amiodarone - Special note

Answer 8

Significant potential drug interactions
The following may potentiate the actions of amiodarone:
 - digoxin
 - phenytoin (dilantin)
 - B blockers
 - Ca2+ channel blocker
 - other antiarrhythmics