Vasodilator Drugs

Potassium Channel Openers

Potassium channel openers prevent the closure of potassium channels by adenosine triphosphate (ATP).

Potassium channels remain closed in the presence of normal levels of ATP. If potassium channels remain open, potassium exit results in hyperpolarization. The calcium channel opening is voltage dependent. Hyperpolarization makes the calcium channel opening more difficult.

Reduced intracellular calcium levels favor relaxation. Potassium channel openers yield potent, long-lasting vasodilation.

Examples: cromokalin, diazoxide, minoxidil, pinacidal