Quinidine is a drug that is also known as an anti-arrhythmic, meaning that it is used to treat abnormalities in heart rate and rhythm. It normalizes the action potential of the heart cells and controls the way potassium, calcium and sodium moves in and out of the heart muscle cells. It is also used in the treatment of malaria. It is available in oral form and injectable forms.

Quinidine is used in the treatment of abnormal heart rate and rhythm disorders, such as atrial and ventricular premature contractions, paroxysmal supraventricular tachycardia, and atrial fibrillation. It is also used in the treatment of malaria.

Quinidine should not be given in people with the following conditions:

  • Hypersensitivity
  • Complete heart block
  • History of thrombocytopenia during treatment with quinine or quinidine
  • Digitalis intoxication

Quinidine may give rise to the following side effects:

  • Muscle weakness
  • Nausea
  • Vomiting
  • Diarrhoea
  • Cinchonism symptoms including impaired hearing, headache, blurred vision, dizziness and vomiting
  • Urticaria and skin reactions
  • Stopping of heart beat
  • Fainting
  • Ventricular fibrillation
  • Thrombocytopenia or low platelet count
  • Exfoliative dermatitis
  • Granulomatous hepatitis (hypersensitivity)
  • Congestive heart failure
  • Heart block
  • Ventricular arrhythmias
  • Tachycardia
  • Seizure
  • Coma


Take extra precautions in people who have the following:

  • Atrial flutter
  • Widening QRS complex in ECG
  • Incomplete AV block in ECG
  • Uncompensated heart failure
  • Myasthenia gravis
  • Acute infections
  • Fever
  • Patients on digitalis
  • Low blood potassium or hypokalaemia
  • Heart attack
  • Gastrointestinal obstruction
  • Liver problems
  • Kidney problems
  • Elderly
  • Prolonged QT interval in ECG
  • History of torsade de pointes
  • Myocarditis
  • Severe myocardial damage
  • Pregnancy
  • Breastfeeding



Quinidine may interact with the following drugs:

  • Antihypertensives
  • Vasodilators
  • Myocardiac depressants
  • Oral anticoagulants
  • Non-depolarizing muscle relaxants
  • Drugs that alkalinise the urine e.g. thiazides
  • Cimetidine
  • Amiodarone
  • Enzyme inducers e.g. phenobarbital, phenytoin and rifampicin
  • Verapamil
  • Procainamide
  • Haloperidol
  • Digitalis

Overdose of Quinidine may lead to the following symptoms:

  • Ventricular arrhythmias
  • Hypotension
  • Nausea
  • Vomiting
  • Tinnitus
  • Blurred vision
  • Confusion
  • Delirium


Available Brand/s:

  • Cardioquine
  • Cin-Quin
  • Duraquin
  • Quinidex
  • Quinora
  • Quinact
  • Quinatime
  • Quinaglute
  • Quinalan

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