Interactions between claritin(loratadine) and Cordarone (amiodarone)
amiodarone and loratadine (Moderate Drug-Drug)
MONITOR: QT interval prolongation and torsade de pointes have been reported with the coadministration of loratadine and amiodarone. A 73-year-old woman receiving chronic therapy with amiodarone developed syncope and multiple episodes of torsade de pointes following the addition of loratadine. The exact mechanism of interaction is unknown. Although QT interval prolongation and torsade de pointes are known adverse effects of amiodarone, they have not been associated with loratadine. It is possible that loratadine competitively inhibits the metabolism of amiodarone via CYP450 3A4, since both are substrates of the isoenzyme.
MANAGEMENT: Until more information is available, it may be appropriate to monitor QT interval whenever loratadine is coadministered with amiodarone. 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.
