Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.
Abnormal heart rhythm: Amiodarone may cause a heart rhythm disturbance called QT prolongation. It can also worsen or trigger an irregular heart beat (arrhythmia). Your doctor will monitor your heart rhythm regularly while you are taking this medication with a test called an electrocardiogram (ECG).
Certain medications (e.g., sotalol, quinidine, thioridazine, chlorpromazine, droperidol, pimozide, moxifloxacin, mefloquine, pentamidine, arsenic trioxide, dolasetron mesylate, probucol, tacrolimus) can increase the risk of a type of abnormal heart rhythm called QT prolongation, and should only be used in combination with amiodarone if the benefit of receiving both medications outweighs the risk of side effects. You are more at risk for this type of abnormal heart rhythm and its complications if you:
- are female
- are older than 65 years of age
- have a family history of sudden cardiac death
- have a history of heart disease or abnormal heart rhythms
- have a slow heart rate
- have congenital prolongation of the QT interval
- have diabetes
- have had a stroke
- have low potassium, magnesium, or calcium levels
- have nutritional deficiencies
Blood potassium and magnesium levels: People with low levels of potassium or magnesium should have these conditions corrected before starting amiodarone, as the risk of worsening abnormal heart rhythms may be increased.
Congestive heart failure: Amiodarone may cause congestive heart failure to worsen. If you have congestive heart failure, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.
General: Due to the potential for serious side effects, amiodarone should only be given by physicians who are experienced in the treatment of abnormal heart rhythms.
Liver disease: Amiodarone may cause liver problems, so your doctor should monitor your liver function regularly. If you have liver disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. People with hepatitis should not take amiodarone.
Lung problems: Amiodarone can cause lung problems (pulmonary fibrosis, permanent scarring of the lungs) that, in some cases, can be fatal. If you experience any difficulty breathing, wheezing, fever, shortness of breath, cough, or coughing up of blood, accompanied by weakness and weight loss while taking amiodarone, tell your doctor immediately.
Skin: Amiodarone may make your skin more sensitive to the sun. Use sunscreen with minimum SPF15 and protective clothing while taking amiodarone. Some people using amiodarone for long-term treatment may develop a blue-grey discoloration of exposed skin. Report any changes in skin colour to your doctor.
Surgery: If you are scheduled for surgery, inform all doctors involved in your care that you are taking amiodarone.
Thyroid disease: Amiodarone can cause thyroid problems (both overactive and underactive). Your doctor will perform tests regularly to monitor your thyroid function prior to and during amiodarone treatment, especially if you are a senior or if you have a history of thyroid problems.
Vision problems: Amiodarone may cause vision problems that may be severe or permanent. Regular eye exams are recommended during amiodarone treatment. If you notice any vision changes or problems, contact your doctor as soon as possible.
Pregnancy: Amiodarone may harm a developing baby if it is taken by the mother during pregnancy. In particular, it has been noted to cause thyroid problems for the baby. This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking amiodarone, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.
Children: The safety and effectiveness of amiodarone for use by children have not been established.