What are the side effects of ivabradine?

Side Effects of Ivabradine

The most common side effect of ivabradine is visual phenomena (phosphenes), which occurs in approximately 3% of patients and is usually transient. 1, 2

Common Side Effects

• Visual disturbances (phosphenes)

  • Enhanced brightness in a limited area of visual field
  • Halos, image decomposition (stroboscopic or kaleidoscopic effects)
  • Colored bright lights or multiple images
  • Usually triggered by sudden variations in light intensity
  • Typically occurs within first 2 months of treatment
  • Generally mild to moderate in intensity
  • Resolves during or after treatment in most cases
  • Rarely leads to treatment discontinuation (<1% of patients) 2, 3

• Bradycardia

  • Occurs in approximately 10% of patients 2
  • Dose-dependent and proportional to baseline heart rate
  • Tends to plateau, making severe bradycardia uncommon 3, 4
  • Less than 1% of patients discontinue therapy due to bradycardia 3

• Cardiovascular effects

  • Hypertension/increased blood pressure (8.9% of patients)
  • Atrial fibrillation (8.3% of patients) 2

Less Common Side Effects

• QT interval prolongation

  • Occurs in proportion to heart rate reduction
  • Not associated with direct effects on ventricular repolarization
  • No direct torsadogenic potential when appropriately corrected for heart rate 3, 4

• Rare postmarketing reports

  • Syncope
  • Hypotension
  • Torsade de pointes (rare)
  • Ventricular fibrillation or tachycardia (rare)
  • Skin reactions: angioedema, erythema, rash, pruritus, urticaria
  • Neurological: vertigo, diplopia, visual impairment 2

Monitoring and Precautions

• Visual symptoms

  • Caution when driving or operating machinery, especially at night
  • Patients should be warned about potential visual disturbances 2

• Cardiac monitoring

  • Monitor for excessive bradycardia, especially when combined with other heart rate-lowering medications
  • Avoid use in patients with sick sinus syndrome 4
  • Contraindicated in very low blood pressure, certain heart conditions, and slow resting heart rate 2

• Drug interactions

  • Avoid grapefruit juice and St. John's wort during treatment
  • Avoid co-administration with medications that can increase ivabradine effects 2
  • Caution with agents that have known rate-lowering or QT-prolonging effects 4

Safety Profile in Clinical Practice

Ivabradine has demonstrated a favorable safety profile in large clinical trials involving over 3,500 patients 3, 4. The benefit-risk assessment is particularly favorable in patients with heart rates ≥70 beats per minute 5. The drug's selective mechanism of action on the sinoatrial node means it does not affect myocardial contractility, relaxation, or peripheral vascular resistance 3.

When used for inappropriate sinus tachycardia, ivabradine effectively reduces maximum and mean heart rates while generally being well-tolerated, with visual phenomena being the most commonly reported side effect 6.