Also Known As: Quinidine, Cardioquin, Quinidex

Quinidine is a pharmaceutical agent that acts as a class I antiarrhythmic agent (Ia) in the heart. It is a stereoisomer of quinine, originally derived from the bark of the cinchona tree.

Like all other class I antiarrhythmic agents, quinidine primarily works by blocking the fast inward sodium current (INa). Quinidine's effect on INa is known as a use dependent block. This means that at higher heart rates, the block increases, while at lower heart rates the block decreases. The effect of blocking the fast inward sodium current causes the phase 0 depolarization of the cardiac action potential to decrease (decreased Vmax).

It also has been used intravenously for the treatment of malaria.

Print this Page

All Treatments

Average Effectiveness

This is the Average effectiveness per ailment as reported by our participants (you).

  • 0 = No improvement or Worse
  • 1 = Slight improvement
  • 2 = Moderate Improvement
  • 3 = Significant Improvement
  • 4 = Cured

Order By

Type of Treatment

Date Range

Minimum Number of Users

Complete a survey on Quinidine to help the CureCrowd community

If you have tried to treat this ailment, please complete the following form to help us better our data, and help guide people to the best possible treatments. CureCrowd is a public resource with absolutely no vested interest in the outcomes of our studies.