Kinidin Durules are given to prevent arrhythmias:

• Recurrence of atrial fibrillation (abnormal or irregular beating of
  the heart)
  
  
• Paroxysmal supraventricular and ventricular tachycardia (rapid beating of the heart)
  
  
• Symptomatic ventricular ectopic beats (irregular beating of the heart)

Kinidin Durules contain the active ingredient quinidine bisulphate:

• Quinidine blocks certain sodium and potassium channels in the heart which results in a slowing of the nerve impulses which control heart contraction (the heart contracts when it pushes out the blood).
  
  
• When the heart beats abnormally quickly or when the normally coordinated beating of its fouir chambers is disturbed, the heart’s ability to pump put blood can diminish. Restoring a more normal situation, and stopping a recurrence of the abnormal heart beat is important.
  
  
• It acts on the beat of the heart in order to slow and regulate the heart rhythm so that irregular and rapid beats are reduced and the heart develops a more regular and normal pattern.
  
  
• It also has a peripheral vasodilating effect (it makes the blood vessels widen) which decreases peripheral vascular resistance.