[header] How to avoid side effects when using flonase (fluticasone ) [title] Learn how flonase works. [step] It's a corticosteroid that stops your body from releasing the chemicals that cause allergies. It is specific to symptoms caused by allergies, and will not relieve similar symptoms with other causes. 
For example, it will stop a runny nose from allergies, but not from a cold. In the past, doctors prescribed it if you had constant allergy symptoms that don't respond to over the counter (otc) medications.