No abstract

Vertex Pharmaceuticals Incorporated.

We evaluated patients with cystic fibrosis (CF) and moderate obstructive lung disease in pulmonary exacerbation in a double-blind placebo-controlled trial to determine the contribution of antibiotic-mediated reduction in sputum bacterial density to clinical improvement. For the first 4 days of study, all patients received bronchodilating aerosols and chest physiotherapy but no antibiotics. During this time, the patients showed significant improvement in mean FVC, FEV1, and maximal midexpiratory flow rate (FEF25-75). In 12 of 13 trials, the patients showed no significant increases in the density of Pseudomonas aeruginosa during these first 4 days. In these 12 trials, the patients were stratified by their initial FVC and randomized to receive either parenteral tobramycin and ticarcillin (n = 7) or placebo (n = 5), in addition to continued aerosol and chest physiotherapy. In the remaining trial, the patient had a significant rise in the density of P. aeruginosa and was assigned to the antibiotic group. During the next 14 days of therapy, the antibiotic group showed significantly (p less than 0.01) greater reductions in log10 colony-forming units (cfu) of P. aeruginosa per gram of sputum and greater increases in FVC, FEV1, and FEF25-75 than did the placebo group. The degree of decrease in log10 cfu P. aeruginosa/g sputum correlated significantly (p less than 0.001) with the degree of improvement in FVC, FEV1, and FEF25-75.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical characteristics most relevant to the decision to treat for a pulmonary exacerbation with antibiotics in cystic fibrosis patients were determined. Variables including age, increased cough frequency and sputum production, new crackles and wheezing, asthma, symptomatic sinusitis, hemoptysis, decreased lung function, weight loss, and new acquisition of Pseudomonas aeruginosa were collected in a large prospective multicenter database (Epidemiologic Study of Cystic Fibrosis). During a 12-month baseline period, data from 11692 patients were compared with data collected during the subsequent 6-month study period. Because pulmonary function assessments were unavailable for patients <6 years of age, separate analyses were done for those <6 and >or=6 years of age. The outcome of interest was any antibiotic treatment in the 6-month study period reported as indicated for an exacerbation. Characteristics with the most discriminatory power were determined using stepwise multiple logistic regression. For patients <6 years of age, the strongest independent associations with treatment for a pulmonary exacerbation were new crackles, increased cough frequency, decline in weight, and increased sputum production. For those patients >or=6 years of age, the strongest independent associations were a relative decrease in percent predicted forced expired volume in 1 sec, increased cough frequency, new crackles, and hemoptysis. The presence of three or more of these key characteristics was strongly associated with the occurrence of a treated exacerbation. The reproducibility of the model over time was confirmed by application to a subsequent set of data. This model has potential for use as an outcome measure in clinical trials, and to assist in treatment decisions for individual patients.