Medication Information Leaflet

What is this medication for?

This medication is used to suppress and prevent the recurrence of abnormal heart rhythm.

Your doctor may use this medication to treat other heart conditions such as Hypertrophic Cardiomyopathy (HCM), which is a condition involving the thickening of the heart muscle. This condition results in obstruction to blood flowing out of the heart, which may cause breathlessness and chest discomfort during exertion.

Disopyramide slows the heart rate and makes the heart contract less forcefully. It also helps reduce obstruction of blood flow in the heart in patients with HCM. This may help to improve symptoms such as breathlessness and chest discomfort. It may be used in combination with other heart medications such as a beta- blocker (e.g. Bisoprolol, Atenolol) or a calcium channel-blocker (e.g. Diltiazem).

How should I take/use this medication?

  • Do not stop taking your medication without checking with your healthcare professional.
  • You may take this medication with or without food.
  • Swallow the capsule with a glass of water. Do not crush, break or chew the capsule

What should I do if I forget to take/use this medication?

If you forget to take a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose. Then take your next dose at the usual time. Do not take two doses to make up for the missed dose.

What precautions should I take?

Inform your healthcare professional if:

  • You are allergic to this medication or any of the other ingredients of this medication
  • You are pregnant, planning to become pregnant, or breastfeeding
  • You have a heart condition known as heart failure
  • You have other heart rhythm disorders (heart block without a working pacemaker, long QT syndrome etc)
  • You have a condition known as Myasthenia gravis (a type of illness characterised by muscle weakness)
  • You have a condition known as Glaucoma
  • You have a condition known as Benign Prostatic Hyperplasia (BPH) or urinary retention
  • You have kidney or liver disease
  • You have low potassium or magnesium levels in your blood
  • You are taking any other medications, including supplements, traditional medications and herbal remedies.

What are some common side-effects of this medication?

  • Dry mouth, headache, dizziness, blurred vision
  • Constipation, stomach bloating and difficulty in passing urine

What are some rare but serious side-effects that I need to seek medical advice immediately?

It is very important that you are on regular follow-up with your doctor to monitor for any possible side-effects. Inform your healthcare professional if you have any of the following side-effects.

This medication may worsen existing abnormal heart rhythm, or cause new irregular heartbeats. Symptoms of abnormal heart rhythm include one or more of the following:

  • Irregular heartbeat e.g. slowed heartbeat or palpitations (a fast heartbeat or ‘racing’ heart)
  • Severe dizziness or fainting spells
  • Difficulties in breathing or chest pain

The symptoms of a drug allergy include one or more of the following:

  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop your medication and see your healthcare professional immediately

What food or medication should I avoid when I take this medication?

Some medications may interact with Disopyramide and affect their effectiveness or increase the risk of side-effects. However, these medications may also be important for your treatment. Inform your healthcare professional of the other medications you are currently taking. Examples include:

  • Certain medications for bacterial infections (e.g. Clarithromycin, Levofloxacin etc)
  • Certain medications for fungal infections (e.g. Itraconazole, Ketoconazole etc)
  • Domperidone (high doses exceeding 30mg per day)
  • Potassium Chloride or Potassium citrate tablets or capsules
  • Certain mood stabilizers (e.g. Citalopram, Quetiapine, etc)
  • Orally inhaled medications (eg ipratropium, glycopyrrolate, tiotropium and umeclidinium) as taking together can increase the risk of side effects which include constipation, fast heartbeat, dry mouth and urinary retention

How should I store this medication?

Store in a cool and dry place, away from direct sunlight. Keep this medication away from children.

How should I throw away this medication safely?

For general waste: Pack this medication into a black trash bag and seal it tightly before throwing it into the rubbish chute or bin.


Please take note that the above is not a complete list of all possible side effects. If you have any concerns about your medication or if you have other side effects that you think are caused by this medication, please consult your doctor or pharmacist.

If you take more than the recommended dose, please seek medical advice immediately. The information provided on this page does not replace information from your healthcare professional. Please consult your healthcare professional for more information.

This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

Last updated on May 2023

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