A beta-blocker
Metoprolol
A beta-blocker used for high blood pressure, heart failure and irregular heart rhythms; never stopped abruptly.
What is Metoprolol?
Metoprolol is a beta-blocker that slows the heart and reduces its workload. It is used for high blood pressure, certain irregular heart rhythms such as atrial fibrillation, angina, and after a heart attack, and in some cases for heart failure.
Education and reference only. This is a plain-language guide to Metoprolol — 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
Metoprolol is a beta-blocker. It slows the heart and reduces its workload, and is used for high blood pressure, for certain irregular heart rhythms (such as atrial fibrillation, where it helps control the rate), and — in a specific form — as part of the long-term treatment of heart failure. It comes in two different forms that are not interchangeable: an immediate-acting form (metoprolol tartrate) and a longer-acting modified-release form (metoprolol succinate), the latter being the one used in heart failure. It is a long-term tablet.
How it works
Metoprolol blocks beta-receptors, chiefly those in the heart, where the body's adrenaline-type signals normally speed up and strengthen the heartbeat. By blunting that stimulation, metoprolol slows the heart rate and lets it beat with less force, which lowers blood pressure and the heart's oxygen demand and helps steady an over-fast rhythm. In heart failure, gently easing the strain on a struggling heart over time can actually help it work better, which is why a slow, careful build-up is used.
Company & origin
Originated / developed by: AB Hässle (Astra, now AstraZeneca).
Metoprolol, a cardioselective beta-blocker, was developed by the Swedish company AB Hässle, a research arm of Astra (now AstraZeneca), in the early 1970s. It was first introduced around 1975 under brands such as Lopresor/Betaloc.
What it treats
Conditions Metoprolol is used for
Practical use
How to take Metoprolol
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it at the same time each day; some forms are taken with or after food as advised.
- Swallow modified-release forms whole and do not crush or chew them.
- Do not stop taking it suddenly, as this can worsen angina or heart problems; any change should be gradual and supervised.
- Be aware it can cause tiredness, cold hands and feet, or slow your pulse.
- Tell your doctor if you have asthma or breathing problems, and report a very slow heartbeat, dizziness or fainting.
Weighing it up
Advantages & disadvantages of Metoprolol
Advantages
- Lowers blood pressure and steadies certain fast or irregular heart rhythms.
- Reduces angina and lowers the risk of further problems after a heart attack.
- Can improve outcomes in some types of heart failure.
- Long-established with extensive clinical experience.
Disadvantages
- Can cause tiredness, cold hands and feet, and a slow heartbeat.
- May worsen breathing in people with asthma or some lung conditions.
- Stopping suddenly can be dangerous, so it must be reduced gradually.
- Can cause dizziness, vivid dreams or low mood in some people.
- May mask the warning signs of low blood sugar in people with diabetes.
Practical use
Good to know
A key safety point is that beta-blockers should never be stopped suddenly: doing so can cause a rebound, with a racing heart, rising blood pressure or chest pain, so any stopping is done by tapering down gradually. The two forms — immediate-release tartrate and modified-release succinate — are not interchangeable, so a switch between them is made deliberately and not by the patient. It is used cautiously in asthma, as beta-blockers can tighten the airways, and it can mask the warning signs of a low blood sugar (such as a fast heartbeat) in people with diabetes.
Who should not take it / use with caution
- People with certain slow or blocked heart rhythms, or untreated heart failure that is not yet stable.
- People with severe asthma or marked airway disease — beta-blockers can trigger wheeze and breathlessness.
- Used with caution in diabetes (it can mask low-blood-sugar warning signs), in significant circulation problems, and never stopped abruptly.
Monitoring
- Heart rate and blood pressure
- Symptoms in heart failure as the dose is built up
- Breathing in people with airway disease
Side effects
- Tiredness, cold hands and feet, and slowing of the heart rate; sometimes dizziness or light-headedness.
- Vivid dreams or disturbed sleep, and occasionally low mood.
- Wheeze or breathlessness in people prone to airway tightening; a very slow heart rate or fainting should be reported.
Key interactions
- Other medicines that slow the heart — such as certain calcium-channel blockers (diltiazem, verapamil) and some heart-rhythm drugs — can add up and slow it too much.
- Care with other blood-pressure-lowering medicines, which can add to its effect.
- Certain antidepressants and other medicines can raise its levels in the body; tell your pharmacist about everything you take.
Available as: Immediate-release tablets (metoprolol tartrate) and modified-release tablets (metoprolol succinate); the two are not interchangeable.
Answers
Metoprolol: frequently asked questions
Can I stop metoprolol suddenly if I feel fine?
No — beta-blockers like metoprolol should never be stopped abruptly. Suddenly stopping can cause a "rebound" with a racing heart, a jump in blood pressure or chest pain. If it needs to stop, your prescriber will reduce it gradually over time.
What is the difference between metoprolol tartrate and metoprolol succinate?
They contain the same active drug but in different forms: tartrate is immediate-acting and succinate is a longer-acting modified-release form (the one used in heart failure). They are not interchangeable, so switching between them is a deliberate prescribing decision — never something to do yourself.
Can I take metoprolol if I have asthma?
Beta-blockers can tighten the airways and are avoided in severe asthma. In milder airway disease they are sometimes used with caution and close monitoring. Always tell your prescriber and pharmacist about any asthma or wheeze before starting it.
Does metoprolol hide the signs of a low blood sugar?
It can. One early warning of a low blood sugar is a fast, pounding heartbeat, and metoprolol blunts that signal. People with diabetes who take it should be aware of other warning signs, such as sweating, and discuss monitoring with their healthcare team.
What is the difference between metoprolol and Betaloc or Lopressor?
They are the same medicine — metoprolol is the generic (active-ingredient) name, while Betaloc and Lopresor are UK brand names and Lopressor and Toprol-XL are US brand names. The active ingredient is identical; the brands differ only in name and, for the long-acting versions, the release form.
The wider class
About Beta-blockers
Metoprolol belongs to the beta-blockers 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: Metoprolol tartrate.
- NICE NG106: Chronic heart failure in adults.
- NICE CKS: Beta-blockers.
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