What are the side effects of amiodarone?

A heart and stethoscope resting on an ECG of the heart

I’ve been prescribed amiodarone for my irregular heart rhythm but developed overactive thyroid as a result. What can I do about it?

Sunil Kochhar says:

Amiodarone is used to treat or prevent heart rhythm disorders, such as atrial fibrillation.

It can be used to treat patients in hospital, especially after heart surgery to prevent atrial fibrillation. It can also be prescribed as a tablet, for example before and after an electrical cardioversion procedure, or if you also have heart failure, or when other medicines haven’t worked. However it can come with significant side effects.

Amiodarone contains iodine, so should not be taken by anyone who is allergic to iodine or by pregnant women.

Amiodarone can be affected by grapefruit, so avoid having grapefruit or grapefruit juice. You should also cover up and wear factor 50 sun cream whenever you are in the sun, as the medicine makes your skin more sensitive to sunlight.

Amiodarone can also affect the thyroid in up to 10 per cent of people. It’s difficult to predict the effect on the thyroid; in some people it can become overactive (hyperthyroidism) and in others it becomes underactive (hypothyroidism).

Amiodarone can also affect the thyroid in up to 10 per cent of people.

An overactive thyroid can cause a range of symptoms, including anxiety, tiredness, dry skin, thinning hair, swelling in the neck and weight loss. An underactive thyroid can lead to weight gain, tiredness, dry skin and swelling in the neck.

Thyroid problems can be treated with further medication or by adjusting your amiodarone dose, which your doctor will need to manage carefully.

If you’re taking amiodarone, look out for these symptoms and have a blood test every six months to check thyroid hormone levels, to ensure that any thyroid problems are detected quickly and managed.

People taking amiodarone should report any new symptoms to their doctor, including worsening of their heart symptoms, feeling light-headed, blurred vision or symptoms of thyroid problems.

If you’re concerned, or want to know more about your medicine, you can also ask a pharmacist for a Medicines Use Review, where we talk to you in more detail about your medicines and side effects.

Meet the expert

Image of Sunil Kocchar

Sunil Kochhar is a community pharmacist in the South East of England with more than 20 years’ experience. As well as working in his NHS pharmacy in Kent, Sunil plays an active role in helping communities stay healthy, including educational events, screening services and local health services. 

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