If current inhibitor

Definition

If current inhibitors are a class of drugs that selectively inhibit the 'funny' pacemaker currents (I_f) in the sinoatrial node. They are primarily used to reduce heart rate in patients with chronic stable angina or heart failure.

5 Must Know Facts For Your Next Test

1. Ivabradine is the most commonly used If current inhibitor.
2. If current inhibitors specifically target the I_f channels in the sinoatrial node, reducing heart rate without affecting myocardial contractility.
3. These drugs are indicated for patients with chronic heart failure who have a resting heart rate of at least 70 beats per minute despite maximum tolerated doses of beta-blockers.
4. Common side effects include bradycardia, hypertension, atrial fibrillation, and visual disturbances such as luminous phenomena (phosphenes).
5. If current inhibitors are contraindicated in patients with acute decompensated heart failure, severe hepatic impairment, and those dependent on pacemakers.

Review Questions

• What is the primary clinical use of If current inhibitors?
• Name one common side effect associated with If current inhibitors.
• In which patient population are If current inhibitors contraindicated?

Related terms

Beta-blockers: A class of drugs that reduce blood pressure by blocking beta-adrenergic receptors.

Sinoatrial Node: The natural pacemaker of the heart where electrical impulses originate.

Phosphenes: Visual sensations experienced as flashes of light, often seen as a side effect of certain medications.