How Do I(f) Current Inhibitors Work?

I(f) current inhibitors or I funny current inhibitors are drugs that lower heart rates and are used in the treatment of angina (a type of chest pain caused by reduced blood flow to the heart). I(f) current inhibitors work by selectively inhibiting I(f) ionic current channels which exhibit predominant expression in the sinoatrial (SA) node and are essential for regulating pacemaker activity in the SA node.

I(f) current channels are a mix of sodium and potassium inward current channels; they are activated on hyperpolarization to a diastolic range of voltages and modulated by the autonomic nervous system. The inward flow of positive ions through these channels results in the spontaneous diastolic depolarization phase, modulating the heart rate.

I(f) current inhibitors selectively block the HCN channel present within the SA node, inhibit I(f) currents, and lower the heart rate without affecting the contractility of the cardiac muscle.

In addition to high blood pressure, central alpha-2 agonists are used in conditions such as:

• Severe heart failure with reduced left ventricular ejection fraction (heart muscle cannot pump the blood as per the body’s requirement)
• Heart failure due to dilated cardiomyopathy (heart muscle cannot pump the blood as per the body’s requirement because the muscles are weakened and dilated)
• Angina
• Tachycardia (increased and irregular heartbeat)

Side effects associated with I(f) current inhibitors may include:

• Blurred vision
• Luminous phenomenon (spontaneous appearance of bright colored light that decreases the ability to see)
• Headache
• Dizziness
• Hypertension (high blood pressure)
• Atrial fibrillation (irregular and rapid heartbeats in the upper chambers of the heart)
• Bradycardia (low heart rate)
• Ventricular arrhythmias (irregular heartbeats in the lower chambers of the heart)
• Atrioventricular block (heart block caused by impairment of electrical impulses traveling from atria to other chambers of the heart)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of I(f) current inhibitors drugs include:

• Ivabradine (Corlanor)