Oxymetazoline solutions inhibit middle ear pathogens and are not ototoxic

Area of Science:

• Otolaryngology
• Microbiology
• Toxicology

Background:

• Otitis media is a common infection requiring effective antimicrobial treatment.
• Oxymetazoline hydrochloride is a widely used nasal decongestant and ophthalmic vasoconstrictor.
• The antimicrobial and ototoxic potential of oxymetazoline preparations requires thorough investigation.

Purpose of the Study:

• To assess the antimicrobial efficacy of commercial oxymetazoline preparations against otitis media pathogens.
• To evaluate the ototoxicity of oxymetazoline solutions and United States Pharmacopeia (USP) oxymetazoline in an animal model.
• To determine the safety and potential utility of oxymetazoline solutions as alternatives to antibiotic ear drops.

Main Methods:

• Antimicrobial activity was determined using disc diffusion assays and minimum inhibitory concentration (MIC) studies.
• Standardized reference strains of common middle ear pathogens were utilized.
• Ototoxicity was assessed by quantifying outer hair cell counts in guinea pig cochlear segments after exposure.

Main Results:

• Oxymetazoline nasal spray and eyedrops demonstrated antimicrobial activity against most tested pathogens, excluding Haemophilus influenzae and Pseudomonas aeruginosa.
• United States Pharmacopeia (USP) oxymetazoline exhibited limited antimicrobial effects.
• Oxymetazoline solutions and USP oxymetazoline showed no ototoxicity, with profiles similar to the saline control group.

Conclusions:

• Commercial oxymetazoline solutions possess antimicrobial properties, likely attributable to preservatives rather than the active ingredient.
• The tested oxymetazoline solutions are not ototoxic to guinea pig cochlear outer hair cells.
• Oxymetazoline solutions represent a potential alternative to broad-spectrum antibiotic drops for post-tympanostomy tube insertion care.