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Indication and dose

Amiodarone is an anti-arrhythmic drug. Used particularly when other drugs have been ineffective or contra-indicated. It is most commonly used in atrial fibrillation and atrial flutter, but is also indicated in:

  • Paroxysmal Supraventricular Tachycardia (PSVT)
  • Nodal + ventricular tachycardia
  • AF + Flutter
  • Ventricular fibrillation
  • Tachyarrhythmias associated with Wolf-Parkinson-White syndrome

Should only be initiated in a hospital or under specialist supervision



  • 200mg TDS for a week
  • Then reduced 200mg BD for another week
  • Followed by a maintenance dose, usually 200mg OD or the minimum dose required to control arrhythmia.

IV Infusion

  • Initially 5mg/kg,  given over 20-120 min with ECG monitoring
  • Subsequent infusions given if necessary according to the patient’s response. MAX DOSE 1.2g DAILY

Ventricular Fibrillation or pulseless ventricular tachycardia refractory to defibrillation:

Initially by IV injection

  • Initially 300mg
  • Dose to be considered after adrenaline has been administered
  • Dose given from a pre-filled syringe/ diluted in 20ml glucose 5%
  • Then by IV injection 150mg if required
  • Followed by IV infusion, 900mg/24hr

Mechanism of action

  • Amiodarone blocks K+ channels, therefore prolonging the refractory period
  • Also effective at blocking Na+, having a high affinity for inactivated channels
  • Anti-adrenergic effects by non-competitively blocking α and β receptors
  • Also has weak Ca2+ blocking effect
  • Slows down the sinus rate and AV conduction, and slightly prolongs the QT interval
  • It can also cause peripheral vasodilation


Contraindications (CI)

  • Severe conduction disturbances (unless pacemaker fitted)
  • Sinus node disease (unless pacemaker fitted)
  • Iodine sensitivity
  • Sinoatrial heart block (except in cardiac arrest)
  • Sinus bradycardia (except in cardiac arrest)
  • Thyroid dysfunction


Specific CI: with IV use

  • Avoid bolus injection in cardiomyopathy
  • Avoid bolus injection in congestive heart failure
  • Avoid in circulatory collapse
  • Avoid in severe arterial hypotension
  • Avoid in severe respiratory failure


Side effects

  • Corneal microdeposits: Many patients develop them
  • Thyroid function: Amiodarone contains Iodine, therefore can cause disorders of thyroid function
  • Hepatotoxicity
  • Pulmonary toxicity
  • Peripheral neuropathy

Pregnancy: Possible risk of neonatal goitre. Only use if there is no other alternative
Breast feeding: Avoid, due to drug present in breast milk. Theoretical risk of neonatal hypothyroidism.

Monitoring tests

  • TFT: Before treatment and every 6 months
  • LFT: Before treatment and every 6 months
  • Serum K+ before treatment
  • Chest X-ray before treatment
  • Patients with high risk of bradycardia should be monitored continuously for 48hr in a clinical setting
  • Patients taking amiodarone (due to other drugs being contraindicated or not tolerated) with daclatasvir and sofosbuvir should be monitored, especially in first week of treatment
  • Patients who stopped amiodarone in the last few months and need to start sofosbuvir and daclatasvir  should be monitored
  • IV amiodarone: Use ECG and resuscitation facilities must be available. Monitor liver transaminases  closely



Amiodarone has a long t1/2  therefore, there is a potential for drug interactions to occur for several weeks or months after treatment has been discontinued.
The list of interactions here are POTENTIALLY SERIOUS in the BNF which is indicated with a black dot and further details of these interactions can be found in the BNF or Stockleys.
Furthermore, there are other interactions which are not potentially serious; nevertheless they still should be monitored and clinical judgement should be used by using pharmacodynamics and pharmacokinetic knowledge.

  • Anti-arrhythmic: Disopyramide or Dronedarone, Flecainide
  • Anti-bacterials: Erythromycin, Levofloxacin, Moxifloxacin, Delamanid, Telithromycin
  • Anticoagulants: Coumarins, Phenindione, Dabigatran
  • Anti-depressants: Citalopram, Escitalopram, Tricyclics
  • Anti-epileptics: Fosphenytoin, Phenytoin
  • Anti-Histamine: Mizolastine
  • Antimalarial: Artemether with Lumefantrine, Artenimol with Piperaquine, chloroquine, hydroxylcholorquine, Mefloquine, Quinine
  • Antimuscarinic: Tolterodine
  • Antipsychotics: Should check BNF with all antipsychotics
  • Antivirals: Should check BNF with all antivirals
  • Atomoxetine
  • Beta-Blockers: especially Sotalol
  • Ca2+ Blockers: Diltiazem, Verapamil
  • Cardiac Glycosides: Digoxin
  • Cobicistat
  • Colchicine
  • Cytotoxics: Bosutinib, Ibrutinib, Vandetanib, Arsenic Trioxide
  • Fingolimod
  • Ivabradine
  • Simvastatin
  • Lithium
  • Pentamidine


 Additional Notes

  • Amiodarone is a phototoxic drug. Therefore, patients will need to be counselled about possible phototoxic reactions. They should be advised to shield their skin from the sun during treatment and also for several months once treatment has been discontinued (wide spectrum sunscreen blocker should be used, which protect against long wave UV and normal visible light)
  • Patients (or carers) taking amiodarone alongside sofosbuvir and daclatasvir should be advised on how to recognise the signs and symptoms of bradycardia and heart block. And should seek medical attention ASAP.
  • Symptoms include: SOB, syncope, light-headedness, palpitations, chest pain and unusual tiredness.

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Dr Tom Leach

Dr Tom Leach MBChB DCH EMCert(ACEM) FRACGP currently works as a GP and an Emergency Department CMO in Australia. He is also a Clinical Associate Lecturer at the Australian National University, and is studying for a Masters of Sports Medicine at the University of Queensland. After graduating from his medical degree at the University of Manchester in 2011, Tom completed his Foundation Training at Bolton Royal Hospital, before moving to Australia in 2013. He started almostadoctor whilst a third year medical student in 2009. Read full bio

This Post Has 2 Comments

  1. 123

    ?max dose @ top in Indication and Dose heading, 1.2mg is written, BNF has 1.2g. Thank you!

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