A heart-rate-lowering medicine
Ivabradine
A medicine that slows the heart rate without lowering blood pressure — used in some people with heart failure or angina whose heart rate stays high despite, or who cannot take, a beta-blocker.
What is Ivabradine?
Ivabradine slows a fast resting heart rate by acting only on the heart’s natural pacemaker, without lowering blood pressure or weakening the heart’s contraction. It is used in certain people with heart failure or angina — usually when a beta-blocker alone is not enough, or cannot be tolerated — and only when the heart’s rhythm is regular (sinus rhythm). A common, harmless side effect is brief visual brightness (like flashes of light).
Education and reference only. This is a plain-language guide to Ivabradine — 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
Ivabradine is a specialised heart medicine whose only job is to slow the heart rate. Unlike beta-blockers, it does not lower blood pressure or reduce the force of the heartbeat — it purely slows the rate. This makes it useful in specific situations: in some people with chronic heart failure who still have a fast heart rate despite a beta-blocker (or who cannot take one), and in some people with angina. It only works when the heart is in its normal regular rhythm (sinus rhythm), not in atrial fibrillation. It is taken as a twice-daily tablet under specialist guidance.
How it works
The heart’s natural pacemaker (the sinus node) sets the heart rate using a specific electrical current known as the "funny" current (I_f). Ivabradine selectively blocks this current, which slows the rate at which the pacemaker fires — and therefore the heart rate — without affecting blood pressure, the force of contraction, or electrical conduction elsewhere in the heart. A slower heart rate lets the heart fill and rest better and reduces its workload, which helps in heart failure and angina.
What it treats
Conditions Ivabradine is used for
Practical use
How to take Ivabradine
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it twice a day with food, as prescribed; the amount is adjusted according to your resting heart rate.
- Do not stop suddenly without advice; your heart rate and symptoms guide any changes.
- Avoid grapefruit juice, which can increase its level.
- Report a very slow pulse, dizziness or breathlessness, and be aware the brief visual brightness is common and usually harmless.
- Have new medicines checked, as several can interact.
Weighing it up
Advantages & disadvantages of Ivabradine
Advantages
- Slows the heart rate without lowering blood pressure or weakening the heartbeat — useful when blood pressure is already low.
- An option when beta-blockers are not enough or not tolerated.
- Can improve symptoms and outcomes in selected people with heart failure.
Disadvantages
- Only works in regular (sinus) rhythm — no use in atrial fibrillation.
- Can cause harmless but noticeable visual brightness (phosphenes).
- Interacts with grapefruit and several medicines; can slow the heart too much.
Practical use
Good to know
Ivabradine only works, and is only appropriate, when the heart is in a regular (sinus) rhythm — it does not help in atrial fibrillation. A distinctive but harmless side effect is a transient brightening of vision, often described as flashes or halos of light (phosphenes), usually triggered by sudden changes in light; this typically settles and rarely needs the medicine to be stopped. The amount is adjusted to keep the resting heart rate in a target range without it becoming too slow. Grapefruit juice can raise its level, and certain medicines interact, so combinations are checked.
Who should not take it / use with caution
- People in atrial fibrillation or with certain slow or irregular heart rhythms, or a very low resting heart rate.
- People with very low blood pressure, severe liver problems, or certain unstable heart conditions.
- Pregnancy and breastfeeding — it is avoided.
Monitoring
- Resting heart rate and rhythm (must be sinus rhythm)
- Blood pressure and symptoms
- Review if visual symptoms are troublesome
Side effects
- Common: brief flashes or increased brightness in the vision (phosphenes), usually harmless and settling with time.
- A slow heart rate (bradycardia), sometimes with dizziness or tiredness.
- Occasionally palpitations or headache; rarely, effects on heart rhythm.
Key interactions
- Grapefruit juice and some medicines (certain antibiotics such as clarithromycin, and antifungals) raise its level.
- Other heart-rate-slowing medicines (beta-blockers, verapamil, diltiazem, digoxin) add to the slowing — combinations are monitored.
- Certain medicines that affect the heart’s QT interval are used with care alongside it.
Available as: Tablets.
Answers
Ivabradine: frequently asked questions
Why am I seeing flashes of light on ivabradine?
These brief bright spots or halos (called phosphenes) are a well-known and usually harmless effect of ivabradine, caused by its action on a current also found in the eye’s retina. They are often triggered by sudden light changes, tend to settle over time, and rarely require stopping the medicine — but do mention them if they bother you.
Why doesn’t ivabradine work if I have atrial fibrillation?
Ivabradine only slows the heart’s natural pacemaker (the sinus node), which is in charge when the heart is in its normal regular rhythm. In atrial fibrillation the rhythm is driven differently, so ivabradine cannot control the rate — other medicines are used instead.
How is ivabradine different from a beta-blocker?
Both slow the heart rate, but a beta-blocker also lowers blood pressure and reduces the force of the heartbeat, while ivabradine only slows the rate. That makes ivabradine useful when the heart rate is still high despite a beta-blocker, or when a beta-blocker cannot be tolerated or would lower blood pressure too much.
Can I drink grapefruit juice with it?
Best avoided — grapefruit juice can raise ivabradine levels and increase side effects. If you regularly drink it, mention this to your pharmacist or doctor.
The wider class
About Heart-rate-lowering medicine (ivabradine)
Ivabradine belongs to the heart-rate-lowering medicine (ivabradine) 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: Ivabradine.
- electronic Medicines Compendium (SmPC): Ivabradine (Procoralan).
- NICE: Chronic heart failure; Stable angina.
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