One of the most common severe side effects of amiodarone is pulmonary toxicity. It causes lung damage, wheezing, shortness of breath, and around 10% of case are deadly.
Amiodarone Lung Disease
Up to 17% of patients who take amiodarone experience pulmonary toxicity. About 10% of these cases are fatal, according to the FDA. Permanent scarring in the lungs — known as pulmonary fibrosis — occurs in about 5-7% of patients who develop lung disease, according to studies reviewing hundreds of case reports.
What is the problem?
Amiodarone is a powerful anti-arrhythmic drug that has been on the market since the 1980s. It is associated with severe toxicities in the lung, thyroid, skin, nerves, liver, and eyes, which is why it it was only approved as a “last-resort” medication.
The problem is that Wyeth Pharmaceuticals marketed amiodarone for less-serious heart problems, which were so effective that it became a first-line treatment for unapproved conditions like atrial fibrillation.
FDA Warnings for Amiodarone
The FDA has ordered Wyeth Pharmaceuticals to stop marketing amiodarone for “off-label” purposes. In 2004, the FDA added a “Black Box” warning label about lung damage, liver disease, and worsening heart rhythm problems.
What is Pulmonary Toxicity?
Pulmonary toxicity occurs when amiodarone accumulates in the lungs. Patients develop scar tissue in the lungs (called “fibrosis”), which narrows the airways and makes it harder to breathe. There is no cure for fibrosis and it can worsen over time.
Symptoms of Lung Damage
- Shortness of breath
- Dry cough
- Fast and shallow breathing
- Unintended weight-loss
- Aching joints and muscles
Amiodarone should be discontinued in patients who are diagnosed with pulmonary toxicity. Their symptoms may actually worsen for several weeks because amiodarone accumulates in the lungs and takes months to be eliminated from the body. In the meantime, corticosteroids like prednisone are recommended.
With early diagnosis, amiodarone lung disease is usually curable. However, advanced lung disease can cause permanent damage, pulmonary fibrosis, or even death. The risk of death is highest for patients who develop Acute Respiratory Distress Syndrome (ARDS).