Cardiac arrest (VF/pulseless VT): Child: 5 mg/kg IV/IO after the third shock; repeat after the fifth shock. [VERIFY against current APLS guidance] Arrhythmia management in children: specialist advice only.
Amiodarone hydrochloride
Class III antiarrhythmic used in the treatment of shock-refractory cardiac arrest (VF/pulseless VT) and in the management of ventricular and supraventricular tachyarrhythmias when other treatments are ineffective or contraindicated.
Indications Preparations and Dose
Indication 1
Cardiac arrest: ventricular fibrillation or pulseless ventricular tachycardia refractory to defibrillation.
Patient Specific Considerations
Give by IV or IO bolus during cardiac arrest per Resuscitation Council UK ALS algorithm; hypotension and bradycardia are not limiting in the arrest setting. Correct hypokalaemia and hypomagnesaemia where identified.
Preparation
IV - Injection
Doses
Adult: Initially 300 mg for 1 dose, dose should be given from a pre-filled syringe or diluted in 20 mL Glucose 5%, consult Resuscitation Council (UK) guidelines for further details, then 150 mg for 1 dose, dose should be given from a pre-filled syringe or diluted in 10 mL Glucose 5%, dose to be given if required; consult Resuscitation Council (UK) guidelines for further details.
Indication 2
Ventricular and supraventricular tachyarrhythmias, including atrial fibrillation, where other drugs are ineffective or contraindicated.
Patient Specific Considerations
Oral treatment should be initiated and titrated under specialist supervision only. Baseline and periodic monitoring required: thyroid function, liver function, serum potassium and chest X-ray. Not for routine initiation at Role 1.
Preparation
Oral - Tablet
Doses
Adult: 200 mg three times a day for 1 week, then reduced to 200 mg twice daily for 1 week, then maintenance 200 mg once daily, dose to be adjusted to the minimum dose required to control arrhythmia, to be reviewed regularly if maintenance dose exceeds 200 mg per day.
Indication 3
Ventricular and supraventricular tachyarrhythmias, including atrial fibrillation, where other drugs are ineffective or contraindicated.
Patient Specific Considerations
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.
Preparation
IV - Infusion
Doses
Adult: Initially 5 mg/kg for 1 dose, to be given over 20–120 minutes with ECG monitoring, subsequent infusions may be given if necessary according to response up to max. 1.2 g per day.
Preparation Guidance
With intravenous use:
Intravenous infusion via central venous catheter recommended if repeated or continuous infusion required, as infusion via peripheral veins may cause pain and inflammation. In emergency use for cardiopulmonary resuscitation, a peripheral venous route can be used if central venous access is not available; the peripheral line should be flushed liberally.
With intravenous use:
For intravenous infusion (Cordarone X®), manufacturer advises give continuously or intermittently in Glucose 5%. Suggested initial infusion volume 250 mL given over 20–120 minutes; for repeat infusions up to 1.2 g in max. 500 mL; should not be diluted to less than 600 micrograms/mL. See cardiopulmonary resuscitation for details of administration in extreme emergency. Incompatible with Sodium Chloride infusion fluids; avoid equipment containing the plasticizer di-2-ethylhexphthalate (DEHP).
With oral use:
For administration by mouth, expert sources advise tablets may be crushed and dispersed in water; injection solution should not be given orally (irritant).
Do not mix with other drugs in the same line.
Legal status / who can administer
POM
Doctors, Paramedics
Major contraindications
In cardiac arrest there are no absolute contraindications. Outside the arrest setting: sinus bradycardia; sino-atrial heart block; severe conduction disturbances or sinus node disease (unless pacemaker fitted); thyroid dysfunction; known iodine hypersensitivity; severe hypotension or circulatory collapse.
Cautions
Elderly (conduction disturbance); heart failure; hypokalaemia (correct before use outside arrest); photosensitivity (advise sun protection); pulmonary toxicity (new or worsening dyspnoea/cough); corneal microdeposits; thyroid disease; very long half-life (approximately 50 days) - effects and interactions persist for weeks to months after stopping.
Avoid: present in milk in significant amounts; risk of neonatal thyroid dysfunction due to iodine content.
Avoid unless there is no alternative: risk of neonatal goitre and thyroid dysfunction; use in cardiac arrest is not withheld on grounds of pregnancy.
Elimination is not primarily hepatic-dependent but hepatotoxicity is recognised: monitor liver function; avoid ongoing therapy in severe impairment. [VERIFY - BNF/SPC]
Raises plasma concentration of digoxin (halve digoxin dose) and enhances the effect of warfarin (monitor INR). Increased risk of ventricular arrhythmia with other QT-prolonging drugs (e.g. quinolones, macrolides, antipsychotics, antimalarials). Increased risk of bradycardia, AV block and myocardial depression with beta-blockers and rate-limiting calcium-channel blockers. Grapefruit juice raises plasma concentration. Interactions persist long after discontinuation due to prolonged half-life.
Lidocaine (shock-refractory VF/pulseless VT where amiodarone is unavailable). [VERIFY - local formulary alternative]
Not compatible with flying duties: both the underlying arrhythmia and the adverse-effect profile (visual, thyroid, pulmonary) are disqualifying; occupational medical review required. [VERIFY against JSP 950 aeromedical standards]
Unfit to dive: underlying arrhythmia is disqualifying for diving duties; refer for occupational medical assessment. [VERIFY against JSP 950 diving standards]
Overdose: bradycardia, hypotension, QT prolongation and ventricular arrhythmia may occur; management is supportive - consult TOXBASE and the National Poisons Information Service. Note the very long elimination half-life when assessing duration of monitoring.