Amiodarone Flashcards
What is the mechanism of action of amiodarone?
- Blocks sodium, calcium, and potassium channels
- Blocks alpha and beta adrenergic receptors
What is the result of amiodarone blocking sodium, calcium, and potassium channels?
It prolongs the cardiac action potential and slows the heart rate
What is the result of amiodarone blocking alpha and beta adrenergic receptors?
It decreases the heart rate and blood pressure
What are the routes of delivery of amiodarone?
IV
PO
What is the problem with administration of amiodarone?
It is highly irritant to the skin
What is done because of amiodarone being highly irritant to the skin?
If a patient requires repeated or continuous infusion of amiodarone, it is recommended to site a central venous catheter
What are the indications for amiodarone?
- CPR
- Rhythm control in AF
- Atrial flutter and tachycardia in WPW
When should amiodarone be given in CPR?
Non-shockable rhythms, or following 3 successful DC shocks
What dose of amiodarone is given for CPR?
300mg IV (diluted in 20ml glucose 5%), then 150mg if required, then IV infusion 900mg/24 hours
What dose of amiodarone is given for arrhythmias?
Initially 5 mg/kg IV, to be given over 20–120 minutes with ECG monitoring, subsequent infusions given if necessary according to response; maximum 1.2 g per day.
What are the contraindications to amiodarone?
- Sinus bradycardia
- Sinoatrial heart block
- Thyroid dysfunction
- Iodine sensitivity
When should amiodarone be used with caution?
- Hypokalaemia
- Severe bradycardia
- Heart failure
- Elderly
What might amiodarone interact with?
- Warfarin
- Digoxin
- Beta blockers
- Calcium channel blockers
- Lithium
- TCAs (SSRIs, amitriptyline etc.)
- Grapefruit juice
What might happen if amiodarone is given with warfarin?
Increased anticoagulant effect
What might happen if amiodarone is given with digoxin?
Increased plasma concentration of digoxin