Safety and efficacy of meropenem (MEPM) in the treatment of suppurative otitis media were evaluated in a multicenter clinical study using a standard protocol. Sensitivity of bacterial isolates to ...MEPM and distribution of the drug into the middle ear mucosa were also investigated. Twenty-five strains of Gram -positive bacteria (including 13 strains of S. aureus) and 13 strains of Gram-negative bacteria (including 4 strains of P. aeruginosa) were isolated from patients with suppurative otitis media. Gram-positive bacteria showed the highest sensitivity to MEPM, second only to imipenem (IPM), while Gram-negative bacteria were more sensitive to MEPM than the other drugs tested (IPM, ceftazidime, cefoperazone, flomoxef, piperacillin, cefotiam), with a MIC80 of 0.39μg/ml and 3.13μg/ml, respectively. Intravenous drip infusion of 0.5g MEPM over 30 min revealed drug concentrations in the middle ear mucosa ranging from 0.69 to 7.83μg/g, while the tissue/blood concentration ratios ranged from 6.27 to 43.3%. Clinical trials involved a total of 52 patients. The most common regimen of administration was twice-a-day in the dose of 0.5g (48 patients, 93.2%) for 3 to 5 days (28 patients, 53.8%). Clinical efficacy of MEPM was evaluated in 46 of the 52 patients, while safety was assessed in all patients. The physician-assessed clinical efficacy rate (“Excellent” plus “Good”) was 80.4% overall (37/46), 85.7% (6/7) for acute suppurative otitis media, and 80.0% (8/10) for chronic suppurative otitis media, while that of the Efficacy Assessment Committee was 78.3% (36/46). The pathogen eradication rate was 86.1% for cases (39 cases) and 87.8% for strains (46 strains). All bacteria species were eradicated except two strains of S. aureus and one strain each of S. epidermidis, Alcaligenes sp. and P. aeruginosa. No side effects occurred in any of the 52 patients, although an increased serum GTP in two patients and positive urinary sugar in one patient were noted. The results of these studies indicate that MEPM is highly effective in the treatment of suppurative otitis media.
