Question

Drug acting on K+ channels include which of the following?

• A. Spironolacton
• B. Amiloride
• C. Nicorandil
• D. Methyldopa

Answer 1

The Correct Option is C

In pharmacology, the action of drugs on ion channels, including potassium (K+) channels, is crucial in understanding their therapeutic effects.
Potassium channels play a significant role in modulating membrane potential and cellular excitability.
Several drugs target K+ channels either directly or indirectly, influencing cardiac, smooth muscle, and nervous system activities. Based on the provided options, let’s evaluate each for their action on K+ channels:

• Spironolactone: This is a potassium-sparing diuretic, but it acts as an antagonist to the aldosterone receptor, not directly on K+ channels.
• Amiloride: Another potassium-sparing diuretic, it blocks epithelial sodium channels in the kidney, decreasing sodium reabsorption and indirectly affecting potassium exchange, but it doesn't directly target K+ channels.
• Nicorandil: Nicorandil uniquely acts as a K+ channel opener. It relaxes smooth muscles, particularly in the cardiovascular system, by activating ATP-sensitive K+ channels, leading to vasodilation.
• Methyldopa: An antihypertensive agent that primarily acts as a centrally acting alpha-2 agonist, with no direct effect on K+ channels.

Therefore, among the given options, Nicorandil is the drug that acts directly on K+ channels.