AMIODARONE AND DISOPYRAMIDE
The QT interval prolonging effects are increased when disopyramide and amiodarone are used together. (18)
Concurrent use should generally be avoided. If concurrent use is essential, the dose of disopyramide should be reduced by 30 to 50% several days after starting amiodarone. The continued need for disopyramide should be monitored, and withdrawal attempted if possible. If disopyramide is added to amiodarone, the initial dose of disopyramide should be about half of the usual recommended dose.