Drug Guide
Ivabradine Hydrochloride
Classification
Therapeutic: Anti-anginal, Heart rate reducing agent
Pharmacological: Selective sinus node If channel inhibitor
FDA Approved Indications
- Chronic heart failure with reduced ejection fraction (HFrEF) in patients with resting heart rate ≥70 bpm as an add-on therapy to standard therapy
- Stable angina pectoris
Mechanism of Action
Ivabradine selectively inhibits the funny current (If) channels in the sinoatrial node, which reduces heart rate without affecting myocardial contractility or blood pressure.
Dosage and Administration
Adult: Starting dose of 5 mg twice daily, titratable to 7.5 mg twice daily based on heart rate and tolerability
Pediatric: Not indicated for pediatric use
Geriatric: Use with caution; start at lower doses due to potential increased sensitivity
Renal Impairment: Adjust dose based on clinical response, use with caution in severe impairment
Hepatic Impairment: Use with caution; dose adjustment may be necessary
Pharmacokinetics
Absorption: Rapid and complete
Distribution: Vd approximately 72 L
Metabolism: Extensively metabolized in the liver, mainly via CYP3A4
Excretion: Primarily in feces; minor renal excretion
Half Life: about 6 hours
Contraindications
- Resting heart rate less than 60 bpm
- Acute decompensated heart failure
- SA or AV block (unless a functioning pacemaker)
- Severe hepatic impairment
Precautions
- Use with caution in patients with atrial fibrillation, significant hepatic impairment, or hypotension. Monitor for visual disturbances and bradycardia.
Adverse Reactions - Common
- Bradycardia (Common)
- Atrial fibrillation (Uncommon)
- Luminous phenomena (visual disturbances) (Common)
- Hypotension (Uncommon)
Adverse Reactions - Serious
- Severe bradycardia, worsening heart failure, atrioventricular block (Serious but less common)
Drug-Drug Interactions
- CYP3A4 inhibitors (e.g., ketoconazole, clarithromycin) increase ivabradine levels.
- CYP3A4 inducers (e.g., rifampin) decrease ivabradine levels.
Drug-Food Interactions
- Grapefruit juice may increase plasma levels.
Drug-Herb Interactions
- St. John's Wort may reduce efficacy by inducing CYP3A4.
Nursing Implications
Assessment: Monitor heart rate, blood pressure, signs of worsening heart failure, and visual disturbances.
Diagnoses:
- Risk for bradycardia
- Risk for decreased cardiac output
Implementation: Administer with food to improve absorption. Monitor HR and BP regularly.
Evaluation: Assess for symptomatic improvement in angina or heart failure; monitor for adverse effects.
Patient/Family Teaching
- Take medication exactly as prescribed.
- Do not discontinue abruptly.
- Report signs of excessive bradycardia, dizziness, visual disturbances, or worsening symptoms.
- Limit grapefruit juice intake.
- Avoid driving or hazardous activities if experiencing dizziness or visual changes.
Special Considerations
Black Box Warnings:
- Do not use in patients with resting HR below 60 bpm or with severe hepatic impairment.
- Caution in the use of CYP3A4 inhibitors or inducers.
Genetic Factors: Genetic variability in CYP3A4 may affect drug levels.
Lab Test Interference: None noted.
Overdose Management
Signs/Symptoms: Severe bradycardia, hypotension, worsening heart failure.
Treatment: Supportive care, atropine for bradycardia, vasopressors for hypotension, temporary pacing if necessary.
Storage and Handling
Storage: Store at room temperature, 20-25°C (68-77°F).
Stability: Stable for the duration of the expiration date when stored properly.