Drug Class Description
Class III antiarrhythmics (anti- arrhythmics).
Generic Name
Amiodarone
Drug Description
Each 3ml ampoule contains 150mg amiodarone hydrochloride.
Presentation
Solution for injection.
Indications
Treatment should be initiated and normally monitored only under hospital or specialist supervision. Cordarone X Intravenous is indicated only for the treatment of severe rhythm disorders not responding to other therapies or when other treatments cannot be used.Tachyarrhythmias associated with Wolff-Parkinson-White syndrome.All types of tachyarrhythmias including supraventricular, nodal and ventricular tachycardias; atrial flutter and fibrillation; ventricular fibrillation; when other drugs cannot be used.Cordarone X Intravenous can be used where a rapid response is required or where oral administration is not possible.
Adult Dosage
Cordarone X Intravenous should only be used when facilities exist for cardiac monitoring, defibrillation, and cardiac pacing.
Cordarone X Intravenous may be used prior to DC cardioversion.
The standard recommended dose is 5mg/kg bodyweight given by intravenous infusion over a period of 20 minutes to 2 hours. This should be administered as a dilute solution in 250ml 5% dextrose. This may be followed by repeat infusion up to 1200mg (approximately 15mg/kg bodyweight) in up to 500ml 5% dextrose per 24 hours, the rate of infusion being adjusted on the basis of clinical response.
In extreme clinical emergency the drug may, at the discretion of the clinician, be given as a slow injection of 150-300mg in 10-20ml 5% dextrose over a minimum of 3 minutes. This should not be repeated for at least 15 minutes. Patients treated in this way with Cordarone X Intravenous must be closely monitored, e.g. in an intensive care unit.
Changeover from Intravenous to Oral therapy
As soon as an adequate response has been obtained, oral therapy should be initiated concomitantly at the usual loading dose (i.e. 200mg three times a day). Cordarone X Intravenous should then be phased out gradually.
Paediatric population
Due to the presence of benzyl alcohol, intravenous amiodarone is usually contraindicated in neonates and premature babies.
No controlled paediatric studies have been undertaken. In published uncontrolled studies effective doses for children were:
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Loading dose: 5mg/kg body weight over 20 minutes to 2 hours
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Maintenance dose: 10 to 15mg/kg/day from a few hours to several days.
If needed, oral therapy may be initiated concomitantly.
Cardiopulmonary resuscitation
The recommended dose for ventricular fibrillations/pulseless ventricular tachycardia resistant to defibrillation is 300 mg (or 5 mg/kg body-weight) diluted in 20 ml 5% dextrose and rapidly injected. An additional 150 mg (or 2.5 mg/kg body-weight) IV dose may be considered if ventricular fibrillation persists.
Child Dosage
Contact manufacturer.
Elderly Dosage
Elderly
As with all patients it is important that the minimum effective dose is used. Whilst there is no evidence that dosage requirements are different for this group of patients they may be more susceptible to bradycardia and conduction defects if too high a dose is employed. Particular attention should be paid to monitoring thyroid function.
Contra Indications
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Sinus bradycardia and sino-atrial heart block. In patients with severe conduction disturbances (high grade AV block, bifascicular or trifascicular block) or sinus node disease, Cordarone X should be used only in conjunction with a pacemaker.
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Evidence or history of thyroid dysfunction. Thyroid function tests should be performed where appropriate prior to therapy in all patients.
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Severe respiratory failure, circulatory collapse, or severe arterial hypotension; hypotension, heart failure and cardiomyopathy are also contra-indications when using Cordarone X Intravenous as a bolus injection.
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Known hypersensitivity to iodine or to amiodarone, or to any of the excipients. (One ampoule contains approximately 56mg iodine).
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The combination of Cordarone X with drugs which may induce torsades de pointes is contra-indicated.
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Cordarone X Intravenous ampoules contain benzyl alcohol. There have been reports of fatal 'gasping syndrome' in neonates (hypotension, bradycardia and cardiovascular collapse) following the administration of intravenous solution containing this preservative. Cordarone X Intravenous should not be given to neonates or premature babies unless the rhythm disturbance is life threatening and either resistant to other medication or alternative therapy is deemed inappropriate.
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Pregnancy - except in exceptional circumstances
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Lactation
All these above contra-indications do not apply to the use of amiodarone for cardiopulmonary resuscitation of shock resistant ventricular fibrillation.
Special Precautions
Benzyl alcohol may cause toxic reactions and allergic reactions in infants and children up to 3 years old.
Cordarone X Intravenous should only be used in a special care unit under continuous monitoring (ECG and blood pressure).
IV infusion is preferred to bolus due to the haemodynamic effects sometimes associated with rapid injection. Circulatory collapse may be precipitated by too rapid administration or overdosage (atropine has been used successfully in such patients presenting with bradycardia).
Repeated or continuous infusion via peripheral veins may lead to injection site reactions. When repeated or continuous infusion is anticipated, administration by a central venous catheter is recommended.
When given by infusion Cordarone X may reduce drop size and, if appropriate, adjustments should be made to the rate of infusion.
Anaesthesia: Before surgery, the anaesthetist should be informed that the patient is taking amiodarone.
Cardiac disorders:
