治療心衰竭 Treatment of chronic heart failure  治療慢性心衰竭

Ivabradine reduces spontaneous pacemaker activity at the cardiac sinus node by blocking the hyperpolarization-activated cyclic nucleotide-gated (HCN) channel to selectively inhibit I(f)-current, thus reducing the heart rate. Ventricular repolarization and myocardial contractility are not affected.

Bioavailability:  ~ 40% due to first pass elimination in gut and liver; AUC increased 20% to 40% with food; Protein binding: 70%; Metabolism: Extensively intestinal and hepatic via CYP3A4; major active metabolite equipotent to ivabradine is the N-desmethylated derivative (S 18982) which is also metabolized by CYP3A4; Elimination Half Life: 6 hrs.

Acute decompensated heart failure, Concomitant use with strong CYP3A4 inhibitors , Pacemaker dependent, Resting heart rate below 60 beats per minute before treatment, Severe hepatic impairment, Severe hypotension (less than 90/50 mmHg), Sick sinus syndrome, sinoatrial block, or third-degree atrioventricular block, except in presence of functioning demand pacemaker, breast-feeding; pregnancy or women of reproductive age not using effective contraception.

X

Ivabradine is contra-indicated during breast-feeding.

Bradycardia (6% to 10%), hypertension (9%), atrial fibrillation (5% to 8%), heart block, sinoatrial arrest; luminous phenomena (phosphenes, 光幻覺). 

Heart failure: Oral: Initial: 5 mg twice daily or 2.5 mg twice daily in patients with a history of conduction defects or who may experience hemodynamic compromise due to bradycardia.
Maximum dose: 7.5 mg twice daily.
Administer with meals. (隨餐服用)