Amiodarone

Key facts

• Amiodarone is a potent anti-arrhythmic used for serious irregular heart rhythms, including atrial fibrillation and life-threatening ventricular arrhythmias.
• It's taken as tablets, often a higher loading dose followed by a lower daily maintenance dose, or given by injection in emergencies. It stays in body tissue for weeks after you stop.
• Amiodarone can slowly affect the thyroid, liver, lungs, and eyes, so baseline and periodic blood tests, a chest X-ray if needed, and eye checks are required, not just watching for symptoms.
• Seek urgent care for new breathlessness or a persistent cough, yellowing of the skin or eyes, or a heart rate that turns very fast, very slow, or irregular.

What amiodarone treats

Amiodarone treats life-threatening ventricular tachycardia and ventricular fibrillation, and it is used for atrial fibrillation and atrial flutter when other drugs have not worked or are unsuitable. It also prevents recurrent arrhythmias, including after cardiac surgery or resuscitation.

How amiodarone works

Amiodarone blocks potassium channels in heart-muscle cells, which lengthens the electrical recovery time between heartbeats, and it also has milder effects on sodium and calcium channels. This slows abnormal electrical conduction through the heart and reduces the tissue's tendency to sustain a chaotic rhythm.

Before you take it

• Tell your prescriber about thyroid disease, liver disease, lung disease, or an iodine allergy. Amiodarone contains iodine and can push the thyroid either underactive or overactive.
• Amiodarone interacts with many medicines, including warfarin, digoxin, statins, other anti-arrhythmics, and some antibiotics such as certain macrolides and fluoroquinolones. Tell every prescriber and pharmacist that you take it, since doses of other drugs often need adjusting.
• Avoid grapefruit juice, and protect your skin from strong sun. Amiodarone can cause severe photosensitivity and, in some people, a blue-grey skin discoloration.
• It is not usually recommended in pregnancy or breastfeeding.

Side effects

Common effects include sun sensitivity, mild nausea, a metallic taste, and a fine tremor.

Seek urgent medical care for:

• New or worsening breathlessness, or a persistent dry cough.
• Yellowing of the skin or eyes, or dark urine.
• Unexplained weight change, or heat or cold intolerance.
• Visual changes, or halos around lights.
• A pulse that turns very slow, very fast, or irregular.

Safety essentials

• Amiodarone requires baseline blood tests for thyroid and liver function before you start, then repeat testing roughly every six months, plus a chest X-ray if lung symptoms appear and periodic eye examination. Organ damage can develop silently, so scheduled checks matter even when you feel well.
• It interacts with a long list of medicines, including blood thinners, other heart drugs, and several antibiotics and antifungals. Always tell any new prescriber or pharmacist that you take amiodarone, even for an unrelated illness.
• Because amiodarone stays in your body for weeks to months after you stop, these interactions and monitoring needs continue well past your last dose.
• Get prompt medical review for breathlessness, cough, jaundice, or new thyroid or visual symptoms.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.