An ultra-short-acting beta-blocker
Esmolol
An intravenous beta-blocker that works for only a few minutes, used in hospital to control fast heart rate and blood pressure.
What is Esmolol?
Esmolol is a beta-blocker given into a vein in hospital that works for only a few minutes. Beta-blockers slow the heart and relax the force of each beat by blocking the effect of adrenaline-like signals. Because esmolol acts very quickly and wears off almost as fast, it is ideal for controlling a fast heart rate or high blood pressure during or just after surgery, or in emergencies, where doctors need precise, second-by-second control. It is given by infusion through a drip and monitored closely. It is sold as Brevibloc.
Education and reference only. This is a plain-language guide to Esmolol — 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
Esmolol is a beta-blocker designed for use in hospital, given directly into a vein. Beta-blockers reduce the effect of adrenaline and similar 'fight or flight' signals on the heart, slowing the heart rate and easing how hard it pumps. What makes esmolol special is that it is ultra-short-acting: it starts working within minutes and wears off within minutes of stopping. This makes it very useful for controlling a fast heart rate or high blood pressure in situations that change quickly, such as around surgery or in emergencies. It is given as a continuous drip (infusion) and is sold under the brand name Brevibloc.
How it works
The heart speeds up and beats harder when adrenaline-like signals act on 'beta' receptors. Esmolol blocks these receptors, so the heart slows and the force of each beat eases, which lowers a fast heart rate and high blood pressure. Its special feature is that it is broken down very rapidly in the blood, so its effect can be turned up or down quickly by changing the drip rate, and it disappears within minutes if the drip is stopped. This fine, fast control is exactly what is needed in fast-changing hospital situations.
Company & origin
Originated / developed by: Generic (long-established).
A very short-acting intravenous beta-blocker used in UK hospitals to control fast heart rate and blood pressure; sold as Brevibloc.
Practical use
How to take Esmolol
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- It is given only in hospital, as a controlled drip (infusion) into a vein by trained staff.
- Your heart rate and blood pressure are monitored closely throughout, so the drip can be adjusted second by second.
- The dose is increased or decreased by changing the infusion rate, and the effect changes within minutes.
- Tell the team about any breathing problems such as asthma, or a very slow heart rate, before it is started.
- It is a short-term hospital medicine and is not something you continue at home.
Weighing it up
Advantages & disadvantages of Esmolol
Advantages
- Works within minutes and wears off within minutes, giving very precise, adjustable control.
- Ideal for fast-changing situations such as surgery, anaesthesia or emergencies.
- If problems arise, the effect fades quickly once the drip is slowed or stopped.
Disadvantages
- Can only be given in hospital through a drip with close monitoring.
- Can lower the heart rate and blood pressure too much if not carefully controlled.
- Like other beta-blockers, it can worsen asthma and is unsuitable for some heart-rhythm problems.
Practical use
Good to know
Esmolol is only used in hospital, given through a drip with close monitoring of the heart rate and blood pressure, because its powerful, fast-acting effect needs careful control. Its great advantage is that if a problem develops, such as the heart rate or blood pressure dropping too low, the effect fades within minutes of slowing or stopping the drip, which is much safer than a long-acting medicine in an emergency. It is often used to keep the heart rate and blood pressure steady during anaesthesia and surgery, or to settle a sudden fast heart rhythm. Like other beta-blockers, it is used with caution in people with asthma, very slow heart rates or certain heart-conduction problems. It is not a medicine people take at home.
Who should not take it / use with caution
- People with a very slow heart rate or certain heart-conduction (heart block) problems should not receive it.
- It is avoided or used with great caution in severe asthma or other serious breathing problems.
- It is not used in people with very low blood pressure or certain types of heart failure without specialist judgement.
Monitoring
- Continuous monitoring of heart rate and blood pressure while the drip is running.
- Watching the drip site for irritation and adjusting the infusion rate to the response.
- Checking breathing in anyone prone to asthma and reviewing other heart medicines.
Side effects
- A heart rate or blood pressure that drops too low, which is managed by adjusting the drip.
- Dizziness, sweating or feeling faint, and irritation or inflammation at the drip site.
- Less commonly, wheezing in people prone to asthma, or temporary confusion.
Key interactions
- Other medicines that slow the heart, such as certain calcium-channel blockers and digoxin, can add to its effect.
- Some anaesthetic and blood-pressure medicines can combine with it to lower blood pressure further.
- Medicines for diabetes may have their warning signs of low blood sugar partly masked.
Available as: A solution given as a drip (infusion) into a vein in hospital.
Answers
Esmolol: frequently asked questions
What is esmolol used for?
It is an intravenous beta-blocker used in hospital to control a fast heart rate or high blood pressure, for example during surgery, anaesthesia or in emergencies.
Why does it work for only a few minutes?
Esmolol is broken down very quickly in the blood, so its effect can be finely adjusted and it wears off within minutes of stopping the drip, which is useful in fast-changing situations.
Is it something I would take at home?
No. It is only given in hospital as a controlled drip with close monitoring of your heart rate and blood pressure.
What happens if my heart rate drops too low?
Because its effect fades within minutes, the team can simply slow or stop the drip, and your heart rate and blood pressure usually recover quickly.
Can I have it if I have asthma?
Beta-blockers can worsen asthma, so tell the team about any breathing problems; they will decide whether it is safe and monitor you closely.
The wider class
About Beta-blocker (ultra-short-acting)
Esmolol belongs to the beta-blocker (ultra-short-acting) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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