Ivabradine Arrow (Ivabradine)

Ivabradine acts on the cardiac If channel to control heart rate in specific cardiovascular conditions.

• Chronic stable angina: reduces the frequency of angina attacks by lowering heart rate.
• Heart failure with reduced ejection fraction: improves exercise capacity and may decrease hospitalisation by decreasing heart rate.

• Ivabradine selectively inhibits the funny (If) current in the sinoatrial node, which slows the spontaneous depolarisation of pacemaker cells. By reducing this inward sodium‑potassium current, the drug lowers the heart rate without affecting myocardial contractility or blood pressure, providing symptom relief in angina and improving haemodynamics in heart failure.

Ivabradine may cause a range of adverse reactions, most of which are related to its heart‑rate‑lowering activity and visual perception.

Common Side Effects

• Bradycardia: heart rate slower than expected.
• Visual disturbances (phosphenes): transient luminous phenomena.
• Headache: mild to moderate intensity.
• Dizziness or light‑headedness.
• Fatigue or general weakness.
• Blurred vision.

Serious or Rare Side Effects

• Symptomatic bradycardia requiring medical intervention.
• Atrial fibrillation or other supraventricular arrhythmias.
• Severe hypotension leading to syncope.
• Significant visual impairment or persistent photopsia.
• Heart block or other conduction abnormalities.
• Allergic reactions such as rash or angioedema.

Before initiating therapy, clinicians should assess patient suitability and monitor for specific risks.

• Hepatic impairment: adjust dose in severe liver disease.
• Baseline heart rate: ensure resting rate is ≥70 bpm before starting.
• Concomitant bradycardic agents: avoid or monitor when combined with beta‑blockers or digoxin.
• Sick sinus syndrome or AV‑block: contraindicated unless a pacemaker is present.
• Hypotension: use cautiously in patients with low blood pressure.
• Store below 25°C: keep in the original pack, protect from moisture.

Ivabradine can interact with several drug classes, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase plasma levels.
• Other bradycardic agents (beta‑blockers, digoxin, non‑dihydropyridine calcium channel blockers): risk of excessive heart‑rate reduction.
• Drugs that prolong AV‑node conduction (e.g., amiodarone): may precipitate heart block.

Moderate Interactions (Monitor Closely)

• Moderate CYP3A4 inhibitors (e.g., diltiazem, verapamil): may modestly raise ivabradine concentrations.
• CYP3A4 inducers (e.g., rifampicin, carbamazepine): may reduce therapeutic effect.
• Other anti‑anginal medications (nitrates, ranolazine): monitor for additive effects on heart rate and blood pressure.