Interactions between e-mycin(erythromycin) and Cordarone (amiodarone)
amiodarone and erythromycin (Major Drug-Drug)
MONITOR CLOSELY: Like other class III antiarrhythmic agents, amiodarone can cause dose-related QT interval prolongation. Coadministration with macrolides, which can also prolong the QT interval, may increase the risk of ventricular arrhythmias including ventricular tachycardia and torsade de pointes because of additive arrhythmogenic potential related to their effects on cardiac conduction. A case of QT interval prolongation and increased QT dispersion has been reported in a patient 3 days after oral azithromycin was added to a regimen that included oral amiodarone. The QTc interval increased from 510 ms to 660 ms and QT dispersion increased from 58 ms to 140 ms. The ECG returned to baseline values 4 days after the azithromycin was discontinued. Erythromycin, clarithromycin, and troleandomycin are also potent inhibitors of CYP450 3A4 and may significantly inhibit the metabolism of amiodarone, resulting in increased serum concentrations of amiodarone and its pharmacologic effects.
MANAGEMENT: Caution and close clinical monitoring are recommended if amiodarone is prescribed with macrolides. Patients should be advised to seek medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, palpitations, or syncope.
