Amiodarone (Cordarone X): reminder of risks of treatment and need for patient monitoring and supervision

Amiodarone has been associated with serious and potentially life-threatening side effects, particularly of the lung, liver, and thyroid gland. We remind healthcare professionals that patients should be supervised and reviewed regularly during treatment. Lung problems may have slow onset but then progress rapidly. Computerised tomography scans may help to confirm a suspected diagnosis of pulmonary toxicity.

Post-publication note: May 2022

A patient card is available for all patients that take amiodarone. This card includes important information on the most serious and potentially life-threatening side-effects (and their symptoms) that may occur during treatment with amiodarone and also reminds patients of the potential for drug to drug interactions.

Advice for healthcare professionals:

  • amiodarone can cause serious adverse reactions affecting the eyes, heart, lung, liver, thyroid gland, skin, and peripheral nervous system
  • review regularly patients on long-term amiodarone treatment – some of these reactions may be life-threatening but onset can be delayed
  • check liver and thyroid function before treatment, and at 6-monthly intervals; thyroid function should also be monitored for several months after discontinuation
  • although routine lung imaging is not necessary in patients taking amiodarone long-term, make patients aware of the need to seek advice if they have new or worsening respiratory symptoms and consider using computerised tomography (CT) scans if pulmonary toxicity is suspected
  • report suspected adverse drug reactions associated with amiodarone on a Yellow Card

Advice for healthcare professionals to give to patients and carers:

  • amiodarone is used to treat serious heart conditions in which your heart beats unevenly or too fast
  • always read the Patient Information Leaflet provided with your medicines and follow the advice on other medicines to avoid and what to do if you have a side effect
  • your doctor may perform tests of your blood, lungs, heartbeat, and eyes before and during treatment – it’s important to have these tests because they can identify if there’s a problem
  • stop taking amiodarone and see a doctor or go to a hospital straight away if you experience any of the following during treatment or in the period after stopping amiodarone:
    • new or worsening shortness of breath or coughing that will not go away
    • yellowing of the skin or eyes (jaundice), feeling tired or sick, loss of appetite, stomach pain, or high temperature
    • weakness, weight loss or weight gain, heat or cold intolerance, hair thinning, sweating, changes in menstrual periods, swelling of the neck (goitre), nervousness, irritability, restlessness, or decreased concentration
    • your heartbeat becomes even more uneven or erratic, or becomes very slow
    • any loss of eyesight

Amiodarone and risk of toxicity

Amiodarone is used to treat certain types of abnormal heart rhythm, including atrial fibrillation and tachyarrhythmias. Amiodarone is generally reserved for situations when other treatments cannot be used or have failed. Treatment should be initiated and monitored under hospital or specialist supervision and in accordance with clinical guidance.

Amiodarone is associated with serious adverse effects in several organ systems including the eyes, gastrointestinal tract, nerves, skin, thyroid, lungs, heart, and liver. Amiodarone interacts with many medications, and advice in the relevant section of the Summary of Product Characteristics (SmPC) should be strictly followed.

Amiodarone has a long plasma half-life of around 50 days, meaning that any adverse effects may persist for a month (or more) after treatment has stopped.

The SmPC for amiodarone contains extensive warnings and precautions. Patients must be monitored closely during treatment.

Adverse effects of amiodarone on the lung

Amiodarone can commonly cause lung inflammation (pneumonitis). In some cases, this inflammation can progress to more serious thickening or scarring (fibrosis), which can be life-threatening. Patients should be carefully evaluated clinically, and consideration given to chest X-rays before starting therapy.

Symptoms of pulmonary toxicity can include shortness of breath (which may be severe and unexplained by the current cardiac status), non-productive cough, and general health deterioration (fatigue, weight loss, and fever). Pulmonary toxicity is usually (but not always) reversible following early withdrawal of amiodarone therapy, with or without corticosteroid therapy.

The MHRA has received a report from a Coroner following the death by multi-organ failure of a woman who had been treated with amiodarone for approximately 5 years and who developed pneumonia during treatment. The Coroner raised a concern that there is no requirement for lung imaging to be undertaken when patients are prescribed amiodarone on a long-term basis.

The MHRA has conducted a review of this issue and sought independent expert advice from the Pharmacovigilance and Cardiovascular, Diabetes, Renal, Respiratory and Allergy Expert Advisory Groups of the Commission on Human Medicines.

Updated advice on lung imaging during amiodarone treatment

Experts involved in our review advised that regular lung imaging during treatment may expose patients to excessive radiation, be alarming for patients, and was unnecessary given that patient-reported worsening of respiratory function is usually a good first indicator of pulmonary toxicity. For this reason, it is important that patients know the symptoms of pulmonary toxicity of which to be aware and the fact this can be serious and may happen at any time during treatment (or in the month after stopping treatment).

The Patient Information Leaflet is being updated to emphasise that respiratory symptoms may get progressively worse and can happen at any time after starting treatment. Additionally, the SmPC for healthcare professionals is being updated to emphasise that computerised tomography (CT) scans are more specific than X-rays and may be therefore more helpful in confirming a suspected diagnosis of lung toxicity.

Reminder on thyroid function monitoring

Amiodarone treatment can commonly lead to hypothyroidism or hyperthyroidism, particularly in patients with a personal history of thyroid disorders in whom treatment is contraindicated.

Thyroid-test levels should be checked before starting treatment, at 6-monthly intervals, and for several months following treatment discontinuation. Regular assessment is recommended in patients whose medical history indicates an increased risk of thyroid dysfunction.

Report suspected adverse drug reactions

Healthcare professionals, patients, and caregivers are asked to submit reports using the Yellow Card scheme electronically using:

When reporting please provide as much information as possible, including information about batch numbers, medical history, any concomitant medication, onset timing, treatment dates, and product brand name.

Report suspected side effects to medicines, vaccines or medical device and diagnostic adverse incidents used in coronavirus (COVID-19) using the dedicated Coronavirus Yellow Card reporting site or the Yellow Card app. See the MHRA website for the latest information on medicines and vaccines for COVID-19.

Article citation: Drug Safety Update volume 15, issue 8: March 2022: 2.

Published 15 March 2022