Kestine Drug Interactions

The interaction of ebastine in combination with ketoconazole and erythromycin (both compounds cause an increase in the QTc interval) has been studied. A pharmacokinetic and pharmacodynamic interaction is observed with both combinations, giving rise to an increase in ebastine plasma levels and to a smaller extent, carebastine levels, without clinically significant pharmacodynamic consequences. The increase in QTc was only approximately 10 mg above that observed with ketoconazole or erythromycin alone. However, caution is recommended when administering Kestine to those patients undergoing concomitant treatment with azole antifungals such as ketoconazole or itraconazole and macrolide antibiotics such as erythromycin.
Pharmacokinetic interactions have been observed when administering ebastine with rifampicin. These interactions can give rise to a decrease in plasma concentrations and a reduction of the antihistamine effects.
There are no described interactions between ebastine and theophylline, warfarin, cimetidine, diazepam and alcohol.
When ebastine is administered with food, both plasma levels and AUC of the main metabolite of ebastine increase between 1.5 and 2 times. This increase does not modify Tmax. The administration of ebastine with food does not modify its clinical effect.
Ebastine can interfere with the results of skin allergy tests, so it is advised not to have them until 5-7 days after suspending treatment.
It can increase the effects of other antihistamines.