• Propafenone is used to treat irregular beating of the heart. Treatment with it will be started by a heart specialist.
  • Swallow the tablets whole (not crushed or chewed), just after a meal.
  • Propafenone may make you feel dizzy or light-headed at first. If this happens, do not drive or use tools or machines.

About propafenone

Type of medicine Anti-arrhythmic
Used for Irregular beating of the heart
Also called Arythmol®
Available as Tablets

Propafenone is used to treat arrhythmias within the heart. An arrhythmia is an irregularity in your heartbeat which causes your heart to skip a beat, beat irregularly, beat very fast or very slow.

Propafenone works by correcting irregular heartbeats to a normal rhythm and by slowing an overactive heart.

Before taking propafenone

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking propafenone it is important that your doctor or pharmacist knows:

  • If you have heart failure or any heart problems other than your abnormal heart rhythm.
  • If you have asthma, other breathing problems, or lung disease.
  • If you have low blood pressure.
  • If you have liver or kidney problems.
  • If you have a pacemaker fitted.
  • If you have been told you have myasthenia gravis (a condition causing muscle weakness).
  • If you are pregnant, trying for a baby or breast-feeding.
  • If you are taking or using any other medicines. This includes any medicines you are taking which are available to buy without a prescription, such as herbal and complementary medicines.
  • If you have ever had an allergic reaction to any medicine.

How to take propafenone

  • Before you start this treatment, read the manufacturer's printed information leaflet from inside your pack. The leaflet will give you more information about propafenone, and a full list of possible side-effects from taking it.
  • Take propafenone exactly as your doctor has told you. It is usually taken two or three times a day. Your doctor will tell you what the right dose is for you. Your dose will also be on the label of your pack.
  • These tablets should be swallowed whole with plenty of water, and should not be crushed or chewed. Take each of your doses with a snack or just after eating a meal.
  • Try to take your doses of propafenone at the same times each day. This will help you to remember to take them.
  • If you do forget to take a dose, take it as soon as you remember (unless it is nearly time for your next dose, in which case leave out the missed dose). Do not take two doses together to make up for a forgotten dose.
  • If you normally drink grapefruit juice regularly, please let your doctor know about this. This is because a chemical in grapefruit juice may increase the amount of propafenone in your bloodstream.

Getting the most from your treatment

  • Try to keep your regular appointments with your doctor. This is so your doctor can check on your progress. Your doctor will want to do some tests, before and during this treatment, to check your heart rhythm and blood pressure.
  • Propafenone may cause blurred vision and make you feel dizzy or tired. If this happens to you, do not drive or use tools or machines, as these effects may put yourself and others at risk.
  • Treatment with propafenone is usually long-term unless you experience an adverse effect. Continue to take the tablets unless you are advised otherwise.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking propafenone.
  • If you buy any medicines, check with a pharmacist that they are safe to take with propafenone.

Can propafenone cause problems?

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. These usually improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following side-effects continue or become troublesome.

Common propafenone side-effects - these affect around 1 in 10 people who take this medicine What can I do if I experience this?
Feeling dizzy, weak or tired, blurred vision If this happens, do not drive or use tools or machines
Palpitations (a feeling that your heart is beating quickly), chest pain Let your doctor know about this
Feeling sick or being sick, abdominal pain Eat simple meals - avoid rich or spicy food. Make sure you take your doses after you have eaten some food
Headache Ask your pharmacist to recommend a suitable painkiller. If the headache continues, speak with your doctor
Dry mouth, or a bitter taste in your mouth Try chewing sugar-free gum or sucking sugar-free sweets
Constipation Try to eat a well-balanced diet and drink plenty of water each day
Diarrhoea Drink plenty of water to replace lost fluids
Feeling anxious, difficulties sleeping, feeling breathless If any of these become troublesome, speak with your doctor for advice

Important: if you experience any of the following rare but possibly serious symptoms, contact your doctor for advice straightaway:

  • An itchy red skin rash, or any difficulties breathing. These could be signs of an allergic reaction.
  • Any yellowing of your skin or the whites of your eyes. These could be signs of a liver problem.
  • If you start to bruise easily, or if you develop a fever and feel generally unwell. These may be signs of a blood disorder.

If you experience any other symptoms which you think may be due to propafenone, discuss them with your doctor or pharmacist.

How to store propafenone

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.