I tried gentamicin in my sinus rinse. Prescribed a vial that I used a syringe to take out the amount and add to my rinse. I did not continue since it was not effective. I had better luck with nebulized antibiotics - breathing through my nose as well. I have read where people get their sinuses flushed with antibiotics periodically by their ENT. Recently, I changed sinus rinse to ChitoRhino packets along with nasalcrom spray and it has been working for me. Good luck