How does it work?

Cordarone X intravenous contains the active ingredient amiodarone, which is a type of medicine called an antiarrhythmic. (NB. Amiodarone injection is also available without a brand name, ie as the generic medicine.) Amiodarone is used to control abnormal heartbeats.

The heart's pumping action is controlled by electrical signals that pass through the heart muscle. The electrical signals cause the two pairs of heart chambers (left and right atria and ventricles) to contract in a regular manner that produces the heartbeat. If the electrical activity in the heart is disturbed for any reason, irregular heartbeats (arrhythmias) of various types can result. These can seriously undermine the pumping action of the heart and result in inefficient blood circulation around the body.

Amiodarone works by slowing the electrical impulses in the heart muscle. This helps to regulate and restore disturbances in the heart rhythm.

Amiodarone is used to treat a variety of different types of fast, abnormal heart rhythms (these are known as tachyarrhythmias). It is used for severe rhythm disorders when other treatments are not effective or cannot be used.

Amiodarone is given by a drip into a vein (intravenous infusion) or by injection when a rapid response is required in an emergency. As soon as an adequate response is obtained, treatment with amiodarone tablets is started and treatment with the injection is phased out. Amiodarone injection may also be given if a person cannot take medicines by mouth.

What is it used for?

• Fast, abnormal heart rhythms (tachyarrhythmias) associated with Wolff-Parkinson-White syndrome
• Fast, abnormal heart rhythms (tachyarrhythmias), including supraventricular, nodal and ventricular tachycardias, atrial fibrillation, atrial flutter and ventricular fibrillation, when other drugs cannot be used.

Warning!

• Amiodarone injection should only be given in a special care unit where continuous monitoring including blood pressure, liver function, lung function and ECG can be performed.
• Amiodarone can cause serious adverse reactions affecting the eyes, heart, lung, liver, thyroid gland, skin and peripheral nervous system. Because these reactions may be delayed, people on long-term treatment should be carefully monitored by their doctor. See the factsheet on Cordarone X tablets for more information about these side effects.

Use with caution in

• Elderly people
• Heart failure
• Low blood pressure
• People with severe electrical conduction disturbances within the heart (high grade atrio-ventricular block, bifascicular or trifascicular block or sinus node disease). This medicine should only be used in conjunction with an artificial pacemaker in these cases.

Not to be used in

• People with conditions that cause breathing to be ineffective, ie to not effectively oxygenate the blood or remove carbon dioxide from the lungs (respiratory failure).
• Failure of the heart to pump blood around the body (circulatory collapse)
• Very low blood pressure in the arteries (severe arterial hypotension)
• Slow heart rate caused by the pacemaker of the heart (sinus bradycardia)
• Failure of the electrical impulse that causes the heart to beat to leave the pacemaker of the heart, resulting in decreased heart function (sino-atrial heart block)
• Current or history of an over or under functioning thyroid gland
• Allergy to iodine
• Pregnancy
• Breastfeeding
• Disease of the heart muscle (cardiomyopathy) (if given as a fast injection)
• Heart failure (if given as a fast injection)
• Neonates or premature babies unless the rhythm disturbance is life threatening and other treatments are ineffective or not suitable

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and Breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• This medicine should not be used during pregnancy unless essential, as it may be harmful to the unborn baby. Seek medical advice from your doctor.
• This medicine passes into breast milk and women taking this medicine should therefore not breastfeed. Seek medical advice from your doctor.

Label warnings

• Avoid exposure of skin to direct sunlight or sun lamps.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

• Injection site reactions, such as pain, redness, swelling, hardening of the skin, infection or pigmentation changes
• Nausea
• Decrease in blood pressure
• Slower than normal heart beat (bradycardia)
• New or worsening abnormal heartbeat
• Interference with functioning of the thyroid gland (over or under activity)
• Lung disorders
• Breathing problems
• Liver problems
• Headache
• Sweating
• Hot flushes
• Severe allergic reaction (anaphylactic shock)
• For other side effects of longer-term amiodarone treatment see the Cordarone X tablets factsheet linked below

The side effects listed above may not include all of the side effects reported by the drug's manufacturer.For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.

There following medicines may increase the risk of a prolonged QT interval on the heart monitoring trace (ECG) if they are taken in combination with amiodarone. As this could increase the risk of an irregular heartbeat called Torsades de Pointes, these medicines must not be taken with amiodarone:

• other anti-arrhythmics, eg disopyramide, procainamide, quinidine, sotalol, bretylium
• intravenous injection of the antibiotics erythromycin, pentamidine or co-trimoxazole
• tricyclic antidepressants, eg doxepin, amitriptyline
• lithium
• the antihistamines terfenadine, astemizole and mizolastine
• antimalarials, eg chloroquine, quinine, mefloquine, halofantrine
• certain antipsychotics, eg chlorpromazine, thioridazine, fluphenazine, pimozide, haloperidol, amisulpiride and sertindole

There is an increased risk of slowed conduction of electrical signals within the heart and a slow heart rate if amiodarone is used with the following; these medicines are not recommended in combination with amiodarone:

• beta-blockers such as propranolol
• the calcium channel blockers diltiazem and verapamil.

The following medicines are not recommended for use in combination with amiodarone because they may lower the amount of potassium or magnesium in the blood, which could increase the risk of side effects on the heart:

• stimulant laxatives, eg senna
• diuretics
• corticosteroids by mouth or injection
• tetracosactide
• intravenous amphotericin.

Amiodarone may increase the blood levels of the following medicines and their dose may therefore need to be reduced if they are used in combination with amiodarone:

• anticoagulants such as warfarin
• ciclosporin
• digoxin
• flecainide
• phenytoin.

Other medicines containing the same active ingredients

Amiodarone tablets and injection are also available as the generic medicine, ie without a brand name.