Study of the distribution of oral ciprofloxacin into the mucosa of the middle ear and the cortical bone of the mastoid process.

This multicentre study evaluates the distribution of ciprofloxacin into the tissue structures of the middle ear following multiple dosing of one 500 mg tablet every 12 h. The samples were taken perioperatively from adult patients due to undergo surgery for chronic otitis. Administration of ciprofloxacin was instigated 9 days prior to the operation. The samples were taken at different intervals after the last dose in order to evaluate variations in concentration with time. The average peak concentrations recorded and the time taken to reach these concentrations were as follows: middle ear mucosa (n = 16): 5.54 +/- 3.46 micrograms/g (3-4 h): cortical bone of the mastoid process (n = 21): 1.07 +/- 1.29 micrograms/g (4 h). The measurements carried out 12 h after the last dose show that concentrations of ciprofloxacin in the middle ear mucosa were still at least as high as the minimum inhibitory concentration for this antibiotic for most of the pathogens implicated in acute exacerbations of chronic otitis. These results suggest that, administered as an oral dose of 500 mg every 12 h, ciprofloxacin may be an effective agent for the treatment of chronic suppurative otitis. These results now need to be backed up by clinical trials.