Measuring Antibiotic Solution Concentration at the Tympanic Membrane Following Self-administration by Patients With Chronic Suppurative Otitis Media

The study team aims to elucidate the potential role of ototopical antibiotic concentration on outcomes in patients diagnosed with chronic suppurative otitis media (CSOM). Chronic suppurative otitis media (CSOM) is characterized by chronic inflammation of the middle ear with persistent discharge from a non-intact tympanic membrane. CSOM is notably associated with a significant burden of disease worldwide. Topical fluoroquinolones are first line therapy for CSOM and are advantageous as compared to oral or intravenous therapy in that these antibiotics avoid systemic side effects and have the potential to locally deliver high antibiotic concentrations, which were thought to be sufficient to overcome all bactericidal resistance to fluoroquinolones.

The investigators will measure antibiotic concentration in aspirates via liquid chromatography with tandem mass spectrometry (LC-MS/MS) from the middle ear of selected subjects with CSOM who are prescribed and instructed to self-administer ototopical ciprofloxacin. Enrolled subjects will be asked to return 3 to 10 days after initial visit to aspirate the middle ear and receive a follow-up evaluation. Furthermore, the subjects will be asked to keep logs of their medication use and to administer the ototopical medication one hour prior to their appointments. The measured ciprofloxacin concentrations will be correlated with clinical outcomes, primarily the time to symptom resolution. The guiding hypothesis is that patient self-administration of ciprofloxacin drops vary in antibiotic delivery with diluted concentrations significantly below the in vitro concentration of the prescribed solution and that these concentrations are below the bactericidal concentration of ciprofloxacin-resistant bacteria.