Amiodarone for Atrial Arrhythmias
Date issued: August 2015
For review: August 2017
Ref: B-348/DN/Cardiology/Amiodarone for Atrial Arrhythmias
Overview
Your doctor has recommended that you take a medication called amiodarone. The purpose of this medication is to help return your heart rhythm to normal or to keep it in a normal rhythm.
For patients with atrial fibrillation (AF), if your heart rhythm is currently constantly irregular, around 20% of people will return to a normal rhythm once taking amiodarone. If this does not occur you may require a simple procedure called a cardioversion to return it to normal. The amiodarone will then help keep it in a normal rhythm.
Amiodarone is a very useful and effective medication for treating atrial arrhythmias and is generally well tolerated. It does however have side effects that can affect different parts of our body.
When starting amiodarone treatment, patients are usually given a loading dose (higher dose) for the first week which is tapered down over the following weeks. It is usually given two or three times a day to begin with and then reduced to a once a day maintenance dose. It is available as 100mg and 200mg tablets.
If you have been asked to take the loading dose and it makes you feel nauseous, it is worth trying taking it once a day, instead of two or three times a day, rather than stopping altogether. You should contact your consultant in this case as it will take longer for the amiodarone to be effective.
Side effects and risks
Amiodarone is generally well tolerated, however as with any medicine, there are potential side effects that may occur which affect different parts of our body.
Skin:
When taking amiodarone the skin can take on a greyish/blue tinge. This will settle when you stop taking amiodarone but can take a long time.
While taking amiodarone you will become more sensitive to sunburn; use sun block and hats to prevent this side effect. Because amiodarone remains in the body for a long time it may be necessary to continue using sun block for a few months after stopping amiodarone.
Thyroid gland:
The thyroid gland produces a hormone which controls the body’s metabolism. Amiodarone can affect this gland, making it both over active (occurs in about 2% of patients) and under active (occurs in about 6% of patients). Your GP will take a blood test every 6 months to check if either of these has developed.
If you experience new symptoms of extreme tiredness or restlessness you should contact your GP to discuss this. Both an over active and under active thyroid can be easily treated.
Eyes:
Small deposits can form on the clear surface that covers the eye (cornea). These deposits are not harmful but may affect your vision when looking at bright lights (particularly at night time – e.g. when driving). A bluish halo is often seen by patients. This occurs in around 1 in 10 patients. It is for this reason that an annual eye examination with an optician is recommended while you are taking amiodarone.
Lungs:
Amiodarone can cause problems with thickening (fibrosis) of some of the structures of the lungs. If you feel you have new problems or worsening problems with shortness of breath you should arrange to see your GP straight away.
Liver:
Amiodarone can rarely cause problems with the function of the liver, which may be improved by reducing the dose of amiodarone. Your doctor will check for any effect on the liver by doing a blood test every 6 months.
Warfarin:
For those patients on warfarin, there is a known interaction with amiodarone. When starting amiodarone your INR level is likely to increase. Your doctor may therefore decrease your warfarin dose when starting amiodarone to prevent your INR going to high. You will initially require more frequent INR testing until your INR has stabilised.
Your doctor will only recommend that you take amiodarone if they feel that the benefits clearly outweigh the risks.
Monitoring for side effects
The effects listed above, although not common, do mean that monitoring is important. You will need to be reviewed with blood tests by your GP 3 months after starting amiodarone and then every 6 months whilst taking it. Please arrange to see your GP if you think you may have developed a side effect before your next review is due.
Alternatives
Other drugs can be used to treat atrial arrhythmias. However they are generally less effective than amiodarone and are often excluded from use in patients who may have additional heart conditions.
How to contact us
If you require any further information please contact either:
The Arrhythmia Care Team - Carolyn Stewart, Dan Newcomb or Debbie Welsh:
01752 431806
Or your Consultant’s secretary via the switchboard: 0845 155 8155
Further information
More information can be found at the following websites:
Arrhythmia Alliance www.heartrhythmcharity.org.uk
AF association www.atrialfibrillation.org.uk
