Activity of ciprofloxacin, ofloxacin, and afrin nasal spray in posttube otorrhea

Abstract

Problem: Oxymetazoline nasal spray (Afrin) is equivalent to ciprofloxacin drops in preventing posttympanostomy tube otorrhea and tube clogging in children. We studied the antimicrobial properties of 2 over-the-counter oxymetazoline preparations and USP oxymetazoline against the 5 bacterial species commonly causing otorrhea and compared this activity with that of ciprofloxacin and ofloxacin. Methods: Haemophilus influenzae (ATCC 33391), Staphylococcus aureus (ATCC 12600), Pseudomonas aeruginosa (ATCC 10145), Moraxella catarrhalis (ATCC 25238), Streptococcus pneumoniae Penicillin resistant (ATCC BAA-343), Streptococcus pneumoniae Penicillin intermediate (ATCC 700906), and Streptococcus pneumoniae Penicillin sensitive (ATCC 33400) were studied. Antibiotic and nonantibiotic susceptibility were determined by disk diffusion assay. The minimal inhibitory concentration (MIC) was measured in liquid cultures. Acidity was determined with indicator pH paper. Results: Afrin nasal spray and Visine LR eyedrops showed activity against Moraxella catarrhalis, Staphylococcus aureus, and Streptococcus pneumoniae, including a highly resistant strain. They had little or no activity against Pseudomonas aeruginosa or Haemophilus influenzae. USP oxymetazoline itself has almost no antimicrobial activity. Both commercial oxymetazoline preparations are moderately acidic. The quinolones had quantitatively greater activity against all pathogens than the oxymetazoline preparations. Conclusion: It is likely that the preservatives and acid pH of Afrin nasal spray account for its ability to prevent posttube otorrhea. Significance: The study shows that Afrin nasal spray is an excellent low-cost alternative to antibiotic drops after tympanostomy tube placement. Support: None reported.