An older medicine for abnormal heart rhythms
Disopyramide
An older medicine used to control certain abnormal heart rhythms.
What is Disopyramide?
Disopyramide is an older medicine used to control certain abnormal heart rhythms, helping the heart beat more regularly. It is usually started and supervised by a specialist because it can sometimes affect the heart's electrical timing (the QT interval) and, in some people, trigger new rhythm problems. It also has strong 'drying' (antimuscarinic) effects, which can cause a dry mouth, blurred vision, constipation and difficulty passing urine, and it can worsen heart failure. Because of these effects, it is used carefully and with monitoring, and is less commonly chosen than some newer options.
Education and reference only. This is a plain-language guide to Disopyramide — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Disopyramide is an antiarrhythmic medicine, meaning it is used to steady the heart when it beats in an abnormal rhythm. It is an older treatment that works on the heart's electrical signals to help restore or maintain a more normal beat. It is usually prescribed by a heart specialist and used with care, partly because of its effects on the heart's electrical timing and partly because of its strong 'drying' side effects on the rest of the body. It is taken by mouth and tends to be reserved for particular situations rather than being a routine first choice.
How it works
Disopyramide acts on the electrical signals that control the heartbeat, slowing the way certain signals spread through the heart muscle so that abnormal rhythms are less likely to take hold. This can help keep the heart in a steadier rhythm. The same effect on the heart's electrical timing can, in some people, lengthen the QT interval and occasionally trigger a new and dangerous rhythm, which is why it needs careful supervision. Separately, it blocks a body signal called acetylcholine, which produces its characteristic 'drying' effects such as dry mouth and difficulty passing urine.
Company & origin
Originated / developed by: Generic (long-established).
An older heart-rhythm medicine used in the UK for certain abnormal heart rhythms, usually under specialist supervision.
What it treats
Conditions Disopyramide is used for
Practical use
How to take Disopyramide
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it regularly as prescribed, at evenly spaced times, to keep its effect on the heart steady.
- Do not stop it suddenly without advice, as your heart rhythm may be affected.
- Tell your prescriber if you have trouble passing urine, a very dry mouth or blurred vision, as these are common effects.
- Mention any prostate problems, glaucoma or heart failure before starting, as it can make these worse.
- Attend monitoring appointments, including heart tracings, so your rhythm and the QT interval can be checked.
Weighing it up
Advantages & disadvantages of Disopyramide
Advantages
- Can help control certain abnormal heart rhythms and keep the heartbeat steadier.
- A long-established medicine with decades of clinical experience.
- Taken by mouth, with regular and slow-release forms available.
Disadvantages
- Can lengthen the heart's electrical timing (the QT interval) and, rarely, trigger new rhythm problems.
- Has strong 'drying' effects, such as dry mouth, blurred vision, constipation and difficulty passing urine.
- Can worsen heart failure and is used with care in glaucoma and prostate problems.
Practical use
Good to know
There are two main things to understand about disopyramide. The first is that, like other rhythm medicines, it can occasionally cause rhythm problems rather than fix them: it can lengthen the heart's electrical timing (the QT interval) and, rarely, trigger a serious rhythm disturbance, so it is started carefully and monitored. The second is its strong 'drying' (antimuscarinic) effects, which commonly cause a dry mouth, blurred vision and constipation, and can make it hard to pass urine, especially in older men or those with prostate problems. It can also raise pressure in the eye, so it is used with care in glaucoma, and it can weaken the heart's pumping, so it is avoided or used cautiously in heart failure. Tell your prescriber about prostate, eye or heart problems before starting.
Who should not take it / use with caution
- People with certain serious heart-rhythm or conduction problems should not take it.
- People with heart failure that is not well controlled should usually avoid it, as it can weaken the heart's pumping.
- It is used with care, or avoided, in people with glaucoma or difficulty passing urine.
- People who have had a serious allergic reaction to it should not take it.
Monitoring
- Regular heart tracings to check the rhythm and the QT interval.
- Watching for signs of worsening heart failure, such as breathlessness or swelling.
- Reviewing 'drying' side effects, especially difficulty passing urine.
Side effects
- Dry mouth, blurred vision and constipation from its 'drying' effects.
- Difficulty passing urine, especially in older men or those with prostate problems.
- Changes in the heart's rhythm, including, rarely, serious new rhythm disturbances.
- Worsening of heart failure, with breathlessness or swelling, which should be reported.
Key interactions
- Other medicines that affect the heart's QT interval can add to the risk, so these must be reviewed.
- Other 'drying' (antimuscarinic) medicines can increase dry mouth, constipation and urinary problems.
- Some medicines change disopyramide levels in the body, so tell your prescriber everything you take.
Available as: Capsules and slow-release tablets taken by mouth.
Answers
Disopyramide: frequently asked questions
What is disopyramide used for?
It is an older medicine used to control certain abnormal heart rhythms, helping the heart to beat more regularly, usually under specialist supervision.
Why does it cause a dry mouth?
Disopyramide has strong 'drying' (antimuscarinic) effects, which commonly cause a dry mouth, blurred vision and constipation and can make it hard to pass urine.
Can it affect my heart rhythm?
Yes, like other rhythm medicines it can lengthen the heart's electrical timing (the QT interval) and rarely trigger new rhythm problems, which is why it is monitored.
Can I take it if I have heart failure?
It can weaken the heart's pumping, so it is usually avoided or used very cautiously in heart failure; your specialist will decide what is safe for you.
Why does my prescriber ask about my prostate or eyes?
Its 'drying' effects can make it hard to pass urine and can raise pressure in the eye, so it is used with care in prostate problems and glaucoma.
Authoritative sources
- BNF
- NICE CKS
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