Discrepancy between antibiotics administered in acute exacerbations of chronic bronchitis and susceptibility of isolated pathogens in respiratory samples: multicentre study in the primary care setting.

A national multicentre prevalence study was undertaken to determine the bacterial strains associated with mild-to-moderate acute exacerbations of chronic bronchitis (AECB) in the primary care setting and the susceptibility of isolated pathogens to different antimicrobials usually prescribed to these patients. All samples were processed by a central reference laboratory. Microdilution tests were carried out to establish the minimum inhibitory concentration (MIC) of various antimicrobials. A double-disk test was performed to establish the macrolide resistance phenotype in Streptococcus pneumoniae. Tests to detect the presence of beta-lactamase in Haemophilus influenzae and Moraxella catarrhalis and polymerase chain reaction to detect the presence of ermB and mefA genes in S. pneumoniae isolates were also performed. A total of 1537 patients were included in the trial and 468 microorganisms were isolated from sputum samples, with the most frequent isolates being S. pneumoniae (34.8%), M. catarrhalis (23.9%) and H. influenzae (12.6%). Resistance rates of pneumococci were 47.2% for penicillin, 1.2% for amoxicillin, 34.3% for macrolides (87.5% of which showed high-level resistance), 13.6% for cefuroxime/axetil and 4.2% for levofloxacin. No bacterial isolates showed resistance to telithromycin. Empirical antibiotic treatment was prescribed to 98.3% of patients, including macrolides to 36.6%, amoxicillin with or without clavulanic acid to 32.3% and fluoroquinolones to 16.1%. In conclusion, S. pneumoniae was the most frequently isolated bacteria in patients with mild-to-moderate AECB. Despite the high rates of resistance of pneumococci to macrolides, they continue to be the most widely used antibiotics in primary care to treat AECB.

Economic evaluation of the antibiotic treatment of exacerbations of chronic bronchitis and COPD in primary care.

This was an observational and economic survey performed in primary care practices throughout Spain to assess the effectiveness and direct medical costs derived from antibiotic treatment of exacerbations of chronic bronchitis (CB) and chronic obstructive pulmonary disease (COPD) in primary care. A total of 252 physicians included 1456 valid patients, 80% were male and the mean age was 68.2 years (SD = 9.8). The antibiotic treatment administered was moxifloxacin in 575 (39.5%), amoxicillin/clavulanate in 460 (31.6%) and clarithromycin in 421 (28.9%). No significant differences were found in clinical and demographic characteristics between treatment arms. The 30-days follow-up visit was completed by 1097 (75%) patients, who were therefore valid for economic evaluation. During follow-up, 440 new medical visits were generated, 69 patients required attendance in emergency wards (6.3%) and 22 were hospitalised (2%). The overall mean cost of exacerbation was Euro 118.58 [95% confidence interval (CI) = Euro 92.2-144.9] and Euro 52.44 (44.2%) were due to therapeutical failure. The mean cost of exacerbation was Euro 111.46 (95% CI = Euro 73.4-149.5) for patients treated with moxifloxacin, Euro 109.45 (95% CI = Euro 68.2-150.7) for those treated with amoxicillin/clavulanic acid and Euro 138.95 (95% CI = Euro 89.4-188.5) for patients receiving clarithromycin. In conclusion, a significant number of patients require new medical interventions after ambulatory treatment of exacerbations of CB or COPD. The mean cost of an exacerbation was Euro 118.58 and failure was responsible for 44.2% of the total cost of exacerbation.