i had post nasal drip for years. a few years ago i was diagnosed with Chronic Sinusitis. then i found out i had nasal polyps. went in and had surgery twice each nostril to remove them. after that my ENT prescribed Dupixent 300mg/2L every two weeks. to keep the polyps cleared up. works great. but i still have CS. which i believe has no real cure. but the Dupixent and Ipratropium Bromide Nasal Solution helps make it more bearable. the solution is a Nasal Spray prescription and you can get both from an ENT or an Allergist. good luck, d