Ketoconazole Emedastine

Herranz U, Rusca A, Assandri A. Emedastine-ketoconazole pharmacokinetic and pharmacodynamic interactions in healthy volunteers. Int J din Pharmacol Ther 2001 39(3) 102-9. 

In a study of the interaction of emedastine difumarate 4 mg bd with ketoconazole 200 mg bd in 12 subjects there was a moderate but statistically significant interaction however, there was no increase in the QT . interval during concomitant therapy (3). The authors concluded that these findings are consistent with the multiple metabohc pathways that supplement the metabolism of emedastine by different enzymatic isoforms of CYP450, and that concomitant treatment with emedastine and ketoconazole in people with normal QT intervals can be undertaken without special precautions. However, it is difficult to determine the precise cardiac risk, if any, posed by the administration of emedastine eye-drops (4). 

Ketoconazole raises the levels of desloratadine, emedastine, fexofenadine but as no adverse cardiac effects were seen these combinations are considered safe. No interaction occurs between ketoconazole and azelastine, cetirizine, intranasal levocabastine, and none is expected with levocetirizine. 

Emedastine 4 mg daily Ketoconazole 200 mg twice daily 5 12 healthy subjects 37% 34% No change 6... 

Etesloratadine, emedastine and fexofenadine levels are raised by ketoconazole but because this does not result in adverse cardiac effects concurrent use is considered safe. Azelastine, cetirizine (and therefore probably... 

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