Amiodarone
CLASS
- class III anti-arrhythmic
MECHANISM OF ACTION
- prolongs cardiac action potential & delaying refractory period
- Delays K+ efflux
- Depresses Na+ influx
- Depresses Ca2+ influx
- Partial antagonism of alpha & beta receptors buy reducing number of receptors or uncoupling adenyl cyclase
PHARMACEUTICS
- PO – 100 & 200mg tablets
- IV – 30 & 50mg/mL ampoules
DOSE
- IV – bolus 5mg/kg in 250mL of 5% dextrose (60min) -> infusion 15mg/kg/day
- PO – load -> 200mg tds reducing to od
INDICATIONS
- stabilisation of supraventricular & ventricular dysrhythmias
ADVERSE EFFECTS
- hypotension
- circulatory collapse
- bradycardia
- nausea + flushing
- Torsades des Pointes
- thyroid disease
- pulmonary fibrosis
- corneal deposits
PHARMACOKINETICS
- Absorption – bioavailability 20-80%
- Distribution – 97% protein bound, Vd very vairable according to dose (1-60L/kg), readily accumulates in tissues
- Metabolism – hepatic
- Elimination – faeces and bile, t1/2 = 4 hours to 50 days depending on dose and route (over 4wks)
EVIDENCE
- Use is recommended in the new Australasian Resuscitation Guidelines – treatment for refractory VF and VT and in stable tachycardia algorithms.
References and Links
- CrashingPatient.com — “Amiodarone, where’s the black box?” by Amal Mattu (2012 video lecture)
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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