Flonase is a rather benign prescription (ie it's not a narcotic or drug that gets abused). If you go into a walk in clinic and tell them you are having pain in your sinuses and have used flonase in the past for similar problems they will probably prescribe it for you. You may be able to get proof from your pharmacy that you have had it prescribed to you. (I don't know if you can but you could check). I hope you get what you need.