Hexarone is amiodarone, in 100 mg and 200 mg tablets. It is one of the most effective medicines available for dangerous heart rhythm disturbances — and one of the most toxic, affecting the thyroid, lungs, liver, eyes, skin and nerves. It requires lifelong monitoring.
What is Hexarone?
The South African Medicine Price Registry lists Hexarone as Schedule 4 tablets containing amiodarone at 100 mg and 200 mg.
Amiodarone is a class III antiarrhythmic, though in practice it acts on all four antiarrhythmic classes at once — blocking potassium, sodium and calcium channels and beta receptors. That breadth is why it works where other rhythm medicines fail.
Two pharmacological facts govern everything about how it is used, and both are unusual:
It has an extraordinarily long half-life — around 50 to 100 days. Amiodarone accumulates in fat, liver, lung and other tissues over weeks. That is why treatment starts with a loading dose for several weeks before dropping to maintenance, and why stopping it does not stop its effects — the drug and its interactions persist for months after the last tablet.
It contains iodine — roughly 37% by weight. A single 200 mg tablet delivers many times the daily iodine requirement. That is the direct cause of the thyroid problems below, and it is why iodine-related tests are affected.
Amiodarone is a specialist medicine. It is prescribed where the rhythm problem is serious and safer options have failed or are unsuitable, and the decision weighs a real risk of organ toxicity against a real risk from the arrhythmia.
What is Hexarone commonly used for?
- Atrial fibrillation and atrial flutter — restoring and maintaining normal rhythm, particularly where other medicines have failed or where there is structural heart disease.
- Ventricular tachycardia and ventricular fibrillation — life-threatening rhythms, where amiodarone is a first-line agent.
- Cardiac arrest, given intravenously during resuscitation for shock-refractory VF.
- Supraventricular tachycardias, including some in Wolff-Parkinson-White syndrome.
- Preventing recurrent arrhythmias in people with implantable defibrillators, reducing the number of shocks.
- Rhythm control after cardiac surgery.
It is not a blood pressure medicine, despite sitting in this category — it treats rhythm, not pressure.
The trade-off is the whole story with this drug. Amiodarone works when other antiarrhythmics do not, and the arrhythmias it treats can kill. It also causes serious toxicity in a meaningful proportion of long-term users. Neither half of that is a reason to stop taking it on your own — but both are reasons to keep every monitoring appointment, and to report new symptoms early rather than assuming they are unrelated.
How Hexarone fits into this medicine category
| Group | Examples | Role |
|---|---|---|
| Antiarrhythmics (class III) | Amiodarone (Hexarone), sotalol, dronedarone | Rhythm control; amiodarone most effective, most toxic |
| Beta blockers | Bisoprolol, carvedilol | Rate control; first-line in many arrhythmias |
| Calcium channel blockers | Diltiazem, verapamil, amlodipine (Ciplavasc) | Rate control; amlodipine is for blood pressure |
| Digoxin | Digoxin | Rate control, particularly with heart failure |
| Anticoagulants | Warfarin, rivaroxaban, apixaban | Stroke prevention in atrial fibrillation |
| Diuretics | Hydrochlorothiazide (Ridaq) | Fluid and blood pressure |
The anticoagulant row matters: controlling the rhythm does not remove the stroke risk of atrial fibrillation. Those are separate decisions, and both are usually needed. See the heart and blood pressure medicines hub.
What to check before using Hexarone
Amiodarone has one of the longest interaction lists in medicine, and because it persists for months, interactions continue long after it is stopped.
Tell every prescriber and pharmacist that you take it, particularly regarding:
- Warfarin. Amiodarone substantially increases its effect. The warfarin dose usually needs halving, with close INR monitoring.
- Digoxin. Levels rise substantially; the dose is usually halved.
- Statins, particularly simvastatin — raised levels increase the risk of muscle damage.
- Other QT-prolonging medicines — some antibiotics, antipsychotics, antidepressants, antimalarials. The risk of dangerous rhythm disturbance compounds.
- Beta blockers, verapamil and diltiazem, which can cause severe bradycardia in combination.
- Grapefruit juice, which raises amiodarone levels.
Also tell your doctor if you have thyroid disease, lung disease, liver disease, eye conditions, or a slow heart rate or heart block, and if you are pregnant or breastfeeding — amiodarone is avoided in both.
The monitoring is not optional. Expect, before starting and periodically thereafter:
- Thyroid function tests — every six months
- Liver function tests
- Chest X-ray and lung function
- Eye examination
- ECG
- Potassium and magnesium levels
Use high-factor sunscreen and cover up. Amiodarone causes marked photosensitivity, and prolonged use can leave a permanent slate-grey or bluish discolouration of sun-exposed skin. In South African sun this is not a minor point.
Do not stop it suddenly without medical advice.
Possible cautions and when to ask a pharmacist or doctor
Common effects include nausea, metallic taste, tremor, sleep disturbance, photosensitivity and — very commonly — corneal microdeposits, tiny golden deposits in the eye seen on examination. These occur in most long-term users, rarely affect vision, and reverse on stopping.
The serious toxicities are the reason for the monitoring, and each has a warning sign worth knowing:
Lungs. New or worsening shortness of breath, a dry cough, or chest pain — amiodarone can cause pulmonary fibrosis, which is potentially fatal and far more treatable when caught early. Report breathlessness promptly and do not attribute it to the heart condition without being checked.
Thyroid. Both overactive (weight loss, palpitations, tremor, heat intolerance, worsening arrhythmia) and underactive (tiredness, weight gain, cold intolerance, low mood). Amiodarone-induced thyrotoxicosis can be difficult to treat.
Liver. Yellowing of the skin or eyes, dark urine, persistent nausea or abdominal pain.
Eyes. Blurred vision, halos, or any sudden loss of vision — optic neuropathy is rare but sight-threatening.
Nerves. Numbness, tingling, weakness or unsteadiness.
Skin. Marked sunburn from little exposure, or grey-blue discolouration.
Get emergency help for:
- Fainting, or a very slow or irregular heartbeat.
- Severe breathlessness, or breathlessness lying flat.
- Chest pain.
- Sudden vision loss.
- A rash with blistering or peeling.
Contact your doctor promptly for any of the warning signs above, if you develop a new cough or breathlessness, if you miss monitoring appointments, or before starting any new medicine — including over-the-counter and herbal products.
Related medicine guides
Frequently asked questions
What is Hexarone 200 mg used for? Serious heart rhythm disturbances — atrial fibrillation and flutter, ventricular tachycardia and fibrillation, and other arrhythmias where safer medicines have failed. It contains amiodarone.
Is it a blood pressure medicine? No. It treats heart rhythm, not blood pressure.
Why do I need so many tests? Amiodarone can affect the thyroid, lungs, liver, eyes and nerves. Monitoring catches those early, when they are far more treatable.
Why does it take weeks to work? It has a half-life of 50 to 100 days and accumulates in tissue, which is why treatment starts with a loading dose.
What happens when I stop it? The drug and its interactions persist for months. Any change should be planned with your doctor.
Why does my skin burn so easily? Amiodarone causes marked photosensitivity. Use high-factor sunscreen and cover up — prolonged use can cause permanent grey-blue discolouration of sun-exposed skin.
I’ve become short of breath — is that my heart? It may be, but amiodarone can cause lung damage. Report new breathlessness or a dry cough promptly rather than assuming.
Does controlling my rhythm mean I can stop my blood thinner? No. Stroke prevention in atrial fibrillation is a separate decision, and usually both are needed.