Effect of topical ciprofloxacin/dexamethasone or dexamethasone alone on acute Streptococcus pneumoniae rhinosinusitis in mice

Otolaryngol Head Neck Surg. 2008 Mar;138(3):340-6. doi: 10.1016/j.otohns.2007.11.023.


Objective: To test whether intranasal ciprofloxacin/dexamethasone or dexamethasone alone affects the course of acute bacterial rhinosinusitis in mice.

Study design: We performed a randomized, double-blind, parallel, placebo-controlled study in mice.

Subjects and methods: Three groups of 10 C57Bl/6 mice were infected with Streptococcus pneumoniae, and then 1 day later randomized to treatment with placebo, ciprofloxacin plus dexamethasone, or dexamethasone. The mice were killed 3 or 10 days after treatment was begun.

Results: The placebo-treated mice became infected and developed an inflammatory cell infiltration in their sinuses. None of the treatments significantly affected the course of the illness.

Conclusion: The lack of topical, intranasal efficacy of ciprofloxacin and dexamethasone could be attributed to subpotent dosage, rapid nasal clearance, or inability of the drops to reach the site of infection. Treatment with dexamethasone neither improved nor worsened the bacterial infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Animals
  • Anti-Infective Agents / administration & dosage*
  • Ciprofloxacin / administration & dosage*
  • Colony Count, Microbial
  • Dexamethasone / administration & dosage*
  • Drug Therapy, Combination
  • Female
  • Flow Cytometry
  • Mice
  • Mice, Inbred C57BL
  • Pneumococcal Infections / drug therapy*
  • Rhinitis / drug therapy*
  • Rhinitis / microbiology*
  • Sinusitis / drug therapy*
  • Sinusitis / microbiology*
  • Tissue and Organ Harvesting


  • Anti-Infective Agents
  • Ciprofloxacin
  • Dexamethasone