Cimetidine moderately raises hydroxyzine levels and considerably raises
loratadine levels, but this is not thought to be of
clinical significance. The manufacturer of mizolastine recommends caution if
cimetidine is taken concurrently because it might increase mizolastine levels and prolong the QT interval. This is a cautious approach since a link between mizolastine and cardiac arrhythmias has not been proven.
No action needed.