DANGEROUS INTERACTION BETWEEN AMIODARONE AND QUINIDINE

Abstract Two patients treated with a combination of amiodarone and quinidine for minor arrhythmia developed atypical ventricular tachycardia ( torsades de pointes ). Both patients had QT-interval prolongation. A combination of amiodarone and quinidine given to a healthy volunteer raised the plasma quinidine concentration and prolonged the QT interval, confirming the observation of a clinically important interaction between the two drugs.