Antiarrhythmics

Antiarrhythmics help control abnormal heart rhythms such as atrial fibrillation (AF), supraventricular tachycardia (SVT) or ventricular tachycardia (VT). Find out how antiarrhythmics work and possible side effects.

Types of antiarrhythmic medication

amiodarone, also called Aratac
digoxin, also called Lanoxin, Lanoxin PG
flecainide, also called Flecainide (Teva), Flecainide BNM
propafenone, also called Rytmonorm
beta blockers
calcium channel blockers

How do antiarrhythmics work?

Antiarrhythmics are used to prevent and treat abnormal heart rhythms, known as arrhythmias. Arrhythmias are caused by a problem with the electrical system of your heart. They can make your heart beat too fast, too slow or irregularly.

Side effects of antiarrhythmics

You may have some unwanted side effects when taking antiarrhythmics. These can include:

tiredness
headache
changes in your vision
feeling dizzy or light-headed
feeling sick (nausea) or being sick (vomiting)
shortness of breath.

Side effects may be worse when you first start the medication but often get better over time. Keep track of any changes.

Talk to your doctor if the side effects are worrying you. The benefits usually outweigh the side effects. Don't stop taking your medication without talking to your doctor first.

Your doctor may also adjust your medication dose so it works best for you.

Amiodarone (Aratac) can cause sensitivity to sunlight. This means you can get sunburnt more easily. Sun protection is important if you're taking this medication.

Call your doctor or Healthline (0800 611 116) if you have:

changes in your heartbeat (either fast, slow or irregular)
chest pain or tightness in your chest
shortness of breath
fainted or feel faint.

Call 111 if you have:

severe chest pain
severe shortness of breath
signs of an allergic reaction, such as itchy skin or rash, swollen lips or tongue.

What checks do I need?

You are likely to have regular blood pressure and heart rate checks.

You may need regular blood tests to check your liver, thyroid and kidney function.

What if I miss a dose of antiarrhythmics?

If you forget to take a dose, take it immediately, then continue as normal the following day. However, if it's almost time for the next dose, skip the missed dose and continue as normal.

Do NOT take a double dose.