Ivabradine

How it works

It selectively inhibits the funny (If) current in the sinoatrial node, slowing the heart rate without affecting myocardial contractility or blood pressure.

Prescribing in practice

• It works only in sinus rhythm and is ineffective and inappropriate in atrial fibrillation, and excessive bradycardia is a key risk.
• Luminous visual phenomena (phosphenes) are characteristic and usually transient but can affect driving in changing light.
• Avoid co-administration with strong CYP3A4 inhibitors and other heart-rate-lowering or QT-affecting drugs that increase bradycardia risk.

Monitoring

Monitor heart rate and rhythm, and review for new atrial fibrillation, particularly after dose changes.

Counselling the patient

• You may notice brief flashes or halos of light, especially with sudden changes in brightness; this is usually harmless.
• Report a slow pulse, dizziness, breathlessness or palpitations.
• Avoid grapefruit juice, which can raise drug levels.

Evidence & guidelines

The SHIFT trial showed ivabradine reduced heart failure hospitalisations in selected patients in sinus rhythm, informing NICE recommendations.