Thank you for your inquiry.
To my knowledge, there are no long term studies, extending over years, regarding the safety of desloratadine. However, based upon clinical experience with antihistamines in general, which have been in use for over 50 years, and the well described safety profile of desloratadine, I personally feel there would be no problem with extended use of this drug on a daily basis for years.
Thank you again for your inquiry and we hope this response is helpful to you.
Phil Lieberman, M.D.