Erythromycin Azelastine

Clinically important, potentially hazardous interactions with alcohol, antihistamines, azatadine, azelastine, brompheniramine, buclizine, chlorpheniramine, cimetidine, clemastine, dexchlorpheniramine, erythromycin, ketoconazole, meclizine, pizotifen, rifampicin, ritonavir... 

There is a case of torsade de pointes possibly due to spiramycin with the sedating antihistamine mequitazine. The situation with erythromycin and loratadine is unclear as one study found that the combination caused a very slight increase in QT interval. Both azithromycin and erythromycin raise fexofenadine levels, but this had no effect on the QT interval, or on adverse events. Azelastine, cetirizine, desloratadine, and intranasal levocabastine seem to be free of clinically relevant interactions with macrolides. 

Fexofenadine levels are raised by both azithromycin and erythromycin but because this does not result in adverse cardiac effects concurrent use is considered safe. Azelastine, cetirizine (and therefore probably its isomer levocetirizine) desloratadine and levocabastine seem to be free from clinically significant pharmacokinetic interactions, and have no cardiac effects, and so may therefore provide suitable alternatives if a non-sedating antihistamine is needed in a patient taking macrolides. 

Azelastine 4 mg twice daily Erythromycin 500 mg three times daily 7 8 healthy subjects No change No change No change 2... 

Sale M, Lyness W, Perhach J, Woosley R, Rosenberg A. Lack of effect of coadministration of erythromycin (ERY) with azelastine (AZ) on pharmacokinetics (PK) or... 

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