I take 3 xyzal daily (total dose 15 mg) for severe hives. i also take olopatadine 0.6% nasal spray (3 sprays each nostril) twice daily. am i at risk for side effects ? cardiac?

This prescription strength antihistamine can interact with a number of other medications so your prescribing physician should be informed about any other meds or supplements you're taking. As for cardiac effects, if you're healthy with no arrhythmia history or prolonged QT interval on EKG, it doesn't prolong your QT interval. No other cardiac warnings are listed.