An intravenous antiarrhythmic to restore a normal heart rhythm
Ibutilide
A medicine given into a vein in hospital to convert recent-onset atrial fibrillation or flutter back to a normal heart rhythm.
What is Ibutilide?
Ibutilide is a specialist antiarrhythmic medicine given into a vein in hospital to convert recent-onset atrial fibrillation or atrial flutter, two types of irregular and often fast heart rhythm, back to a normal rhythm. It works by changing the electrical activity in the heart so the normal rhythm can take over. Because it can affect the heart's electrical timing, it can cause a dangerous rhythm disturbance called torsades de pointes, so it is given only in hospital with continuous heart (ECG) monitoring during and for a period after the infusion, with resuscitation facilities to hand.
Education and reference only. This is a plain-language guide to Ibutilide — 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
Ibutilide is an antiarrhythmic medicine, meaning it acts on the heart's electrical system to restore a normal rhythm. It is used in hospital to convert recent-onset atrial fibrillation or atrial flutter, conditions in which the upper chambers of the heart beat in a disorganised or very fast way, back to a regular, normal rhythm. It is given as an infusion into a vein under close supervision. It is a specialist treatment used for a specific purpose, restoring rhythm in the right patients, and is not a medicine that is taken at home.
How it works
The heartbeat is controlled by electrical signals that pass through the heart muscle in an organised way. In atrial fibrillation and atrial flutter, these signals become disorganised, so the upper chambers quiver or beat too fast. Ibutilide alters the way the heart cells reset between beats (it prolongs the recovery phase), which can interrupt the abnormal circuit and let the heart's normal rhythm take over. This same effect on the heart's electrical timing, however, can sometimes trigger a dangerous abnormal rhythm, which is why it is used only with continuous monitoring.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist medicine used in hospital in the UK to convert recent-onset atrial fibrillation or atrial flutter back to a normal heart rhythm.
What it treats
Conditions Ibutilide is used for
Practical use
How to take Ibutilide
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given only in hospital, as an infusion into a vein, by a team experienced in managing heart rhythms.
- Your heart will be continuously monitored with an ECG during the infusion and for a period afterwards.
- The team usually checks and corrects blood salts such as potassium and magnesium beforehand to lower the risk of a rhythm problem.
- Tell the team about all your medicines, especially any that affect the heart's rhythm.
- It is a one-off treatment to restore rhythm, not a medicine you continue at home.
Weighing it up
Advantages & disadvantages of Ibutilide
Advantages
- Can quickly convert recent-onset atrial fibrillation or atrial flutter back to a normal rhythm.
- Offers a medicine-based way to restore rhythm without needing an electric shock in some patients.
- Works best in recent-onset rhythm problems, where it has a good chance of success.
Disadvantages
- Can cause a dangerous abnormal rhythm (torsades de pointes), so it needs continuous ECG monitoring.
- Can only be given in hospital with resuscitation facilities available.
- Less likely to work in long-standing rhythm problems, and not suitable for everyone.
Practical use
Good to know
The single most important point about ibutilide is its safety profile: by changing the heart's electrical timing (prolonging the QT interval), it can occasionally trigger a serious abnormal rhythm called torsades de pointes. For this reason it is given only in hospital, with continuous heart-tracing (ECG) monitoring during the infusion and for a period afterwards, and with resuscitation equipment and trained staff immediately available. Before it is used, the team usually checks and corrects blood salts such as potassium and magnesium, because low levels increase the risk. It is used for recent-onset atrial fibrillation or flutter, where it has the best chance of working, and the team will weigh up whether it is the right choice compared with other ways of restoring rhythm. It is a one-off hospital treatment rather than an ongoing medicine.
Who should not take it / use with caution
- People who have had a serious allergic reaction to ibutilide should not receive it.
- It is avoided in people who already have a long QT interval or a history of torsades de pointes.
- It is used with great caution, or avoided, in people with significant heart failure or uncorrected low potassium or magnesium, under specialist judgement.
Monitoring
- Continuous ECG (heart-tracing) monitoring during the infusion and for a period afterwards.
- Checking blood salts such as potassium and magnesium before treatment.
- Watching blood pressure and overall heart rhythm throughout.
Side effects
- Abnormal heart rhythms, including, importantly, torsades de pointes, which is why continuous monitoring is essential.
- A temporarily fast, slow or irregular heartbeat around the time of the infusion.
- Nausea, headache or low blood pressure in some people.
Key interactions
- Other medicines that prolong the QT interval add to the risk of a dangerous rhythm, so they are reviewed carefully.
- Low potassium or magnesium, sometimes caused by other medicines such as certain water tablets, increases the risk and is corrected first.
- Tell the team about all your medicines and any heart conditions before it is given.
Available as: A solution given as an infusion into a vein in hospital.
Answers
Ibutilide: frequently asked questions
What is ibutilide used for?
It is given into a vein in hospital to convert recent-onset atrial fibrillation or atrial flutter back to a normal heart rhythm.
Why does my heart need continuous monitoring?
Ibutilide changes the heart's electrical timing and can occasionally trigger a dangerous rhythm called torsades de pointes, so it is given with continuous ECG monitoring during and after the infusion, with resuscitation facilities available.
Why are my blood salts checked first?
Low levels of potassium or magnesium increase the risk of a dangerous rhythm, so the team usually checks and corrects these before giving ibutilide.
Is it taken at home?
No; it is a one-off treatment given only in hospital under close monitoring, not a medicine you continue at home.
Does it always work?
It works best in recent-onset atrial fibrillation or flutter and is more likely to succeed then; it is less likely to work in long-standing rhythm problems and is not suitable for everyone.
Authoritative sources
- BNF
- NICE CKS
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