It is alkaloid from Cinchona bark-the dextroisomer of quinine & has been noted to suppress ‘rebellious palpitation’. Quinidine increase threshold for excitation and reduces conduction velocity, thus limits the spread of arrhythmia.


Mode of Action: 

Quinidine produces its action by blocking inward sodium current. Its action is use dependent means at higher heart rates blocking will increase and at lower heart rate, blocking will be decreased.
Quinidine inhibits Na+/K+-ATPase similar to digitalis glycosides.


Indications: 

Atrial Fibrillation or flutter, Paroxysmal supra ventricular tachycardia, ventricular premature beats & ventricular tachycardia, uncomplicated falciparum malaria etc

Side effects: 

A.V. dissociation, nausea, vomiting, diarrhea, vertigo, ringing in ear, deafness, visual disturbance, headache, asthma, muscle weakness, urticaria etc

Dosage Forms:

Quinidine 100 mg tablets
Quinidine 200 mg tablets

Combinations of Quinidine:

Brand Name (Company Name):

Natcardine (Franco Indian Remedies)
Quinidine (Glaxo Smithkline Pharmaceuticals Ltd.)