<p>Systemically administered Ketoconazole and Erythromycin, antiarrythmics e.g. Amiodarone moderately increase the plasma concentration of Mizolastine. This could increase the risk of arrythmias. Concurrent use of other potent inhibitor of the cytochrome P 450 3A4 enzyme e.g. Ciclosporin should be approached with caution. No potentiation of the sedation and the alteration in performance caused by alcohol with Mizolastine has been observed.</p>