it is a good drug for nasal allergies and also, for a fair number of people, effective treatment for asthma. And it is safe,
not a cause of significant liver disease, and
not associated with other side effects, deemed serious.
To the best of our current knowledge, the long term use of a nasal steroid, as directed, does not pose a problem. However, if your symptoms diminish during certain seasons, you may not and should not take the drug during those times.