Could Over Usage Of Zyrtec Cause Histamine Imbalance?

Hi.....l have no allergies but find it hard to get more than six hours sleep a night until one evening l had my daughters Zyrtec when l had a stuffy nose from a cold and had such an amazing sleep! Since then l use one maybe once a fortnight when l desparately need a good sleep. Is this ok? Can l use them more often or would l end up with a histamine imbalance?