Quinidine is used to treat certain types of irregular heartbeats. Quinidine is in a class of medications called antiarrhythmic medications. It works by making your heart more resistant to abnormal activity.

What is the action of quinidine?

Quinidine acts on sodium channels on the neuronal cell membrane, limiting the spread of seizure activity and reducing seizure propagation. The antiarrhythmic actions are mediated through effects on sodium channels in Purkinje fibers.

What does quinidine do to the heart?

Quinidine is a Class 1a antiarrhythmic. It works in the heart to slow down the electrical impulses that make the heart muscle contract and pump blood. During an arrhythmia, heart muscle contractions are irregular. Slowing down the electrical impulses can regulate the heartbeat and stop the arrhythmia.