Ivabradine is an anti-anginal drug; i.e. it is used to treat angina in patients with coronary artery disease similarly to beta-blockers, calcium channel blockers, nitrates, and ranolazine. It is also used for the treatment of heart failure and inappropriate sinus tachycardia. Ivabradine slows down the heartbeat so that the heart does not have to work as hard. Ivabradine must not be used in atrial fibrillation and patients with heart rate below 75 beats per minute. Ivabradine is normally well tolerated, but possible side effects include slow heart rate manifesting with tiredness, dizziness, and lethargy.