Ivabradine Krka (Ivabradine)

• Ivabradine acts on the cardiac If current to control heart rate in conditions where rate reduction improves outcomes.
• Chronic stable angina: improves exercise tolerance and reduces the frequency of angina attacks.
• Heart failure (NYHA class II‑III): lowers heart rate, alleviates symptoms and may decrease hospitalisations.
• Ischemic heart disease: helps control heart rate when beta‑blockers are insufficient or not tolerated.

• Ivabradine selectively inhibits the funny (If) current in the sinoatrial node, which slows depolarisation of pacemaker cells. By reducing the slope of phase 4 depolarisation, it lowers heart rate without affecting myocardial contractility, ventricular repolarisation, or systemic vascular resistance.

Ivabradine may cause a range of adverse reactions, most of which are mild to moderate in severity.

Common Side Effects

• Bradycardia: heart rate falls below the desired range.
• Visual disturbances (phosphenes): transient luminous phenomena.
• Headache: mild to moderate intensity.
• Dizziness or light‑headedness.
• Fatigue or general weakness.
• Nausea or gastrointestinal discomfort.

Serious or Rare Side Effects

• Symptomatic bradycardia requiring medical intervention.
• Atrial fibrillation or other significant arrhythmias.
• Severe hypotension leading to syncope.
• High‑grade atrioventricular block.

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

• Heart rate monitoring: ensure resting heart rate remains above 50 bpm.
• Hepatic impairment: use with caution in moderate to severe liver disease.
• Concomitant bradycardic agents: avoid excessive heart‑rate reduction when combined with beta‑blockers or digoxin.
• Sick sinus syndrome or atrioventricular block: contraindicated unless a pacemaker is present.
• Pregnancy and lactation: safety not established; avoid unless benefits outweigh risks.
• Store at room temperature: keep in the original pack, protect from moisture and direct sunlight.

Ivabradine can interact with several drug classes, influencing heart rate or plasma concentrations.

Major Interactions (Avoid)

• Strong CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin): may increase ivabradine levels.
• Co‑administration with other bradycardic agents (beta‑blockers, digoxin): risk of excessive heart‑rate reduction.
• Other If‑channel inhibitors: additive effect on pacemaker activity.

Moderate Interactions (Monitor Closely)

• CYP3A4 inducers (e.g., rifampicin, carbamazepine): may reduce efficacy.
• Antihypertensive drugs: potential additive blood‑pressure lowering.
• QT‑prolonging agents: may increase arrhythmia risk, requiring ECG monitoring.