Hi. Thanks for your query. Your history of cold along with lingering sore throat and chest congestion needs flonase as well oral decongestants and antibiotics if required. The trivial things if not treated properly may cause much of the problems. The steroid in the flonase is so small that it does not cause any systemic side effects hence stop worrying and continue without any doubts. Natural: Take plain water steam inhalations. Warm liquids and food for good recovery. Bed rest helps to recover faster.