Use of Aerosolized Antibiotics in Patients With Cystic Fibrosis: Studies Using Polymyxins
Tobramycin significantly improved pulmonary function, decreased sputum P aeruginosa bacterial density, reduced hospitalizations, and reduced the use of other antipseudomonal antibiotics. The tobramycin treatment effect on FEV1 percent predicted in both trials was approximately 12%. antibiotics buy
In all subgroups analyzed, stratified by age, gender, disease severity, and concurrent use of rhDNase (Pulmozyme; Genentech; South San Francisco, CA), tobramycin-treated patients had greater improvements in pulmonary function test (PFT) results and greater reductions in P aeruginosa sputum bacterial density than patients receiving standard therapy without tobramycin.
Adjunctive Therapy for CF Pulmonary Exacerbations: Two studies have investigated the addition of aerosolized antibiotics to an antibiotic regimen in patients being treated for a pulmonary exacerba-tion.’ Both studies found similar improvement in pulmonary function and clinical measurements in the treatment groups whether or not patients received aerosolized aminoglycoside therapy. In one study, a temporary clearance of P aeruginosa from the sputum was seen in 70% of patients receiving inhaled antibiotic as compared to 41% of patients treated with IV antibiotics alone. The significance of this is unknown. To our knowledge, no study has assessed the efficacy of inhaled antibiotics in place of IV antibiotics for treatment of a pulmonary exacerbation.
Studies Using Polymyxins
Polypeptide antibiotics of the polymyxin class are poorly absorbed across mucosal surfaces, so that aerosol therapy offers the theoretical advantage of high respiratory tract levels with low systemic absorption, and a low risk of emergence of polymyxin-resistant P aeruginosa.
Suppression Therapy: The therapeutic efficacy of aerosol polymyxin (Parke-Davis; Morris Plains, NJ) as suppression therapy in CF patients has been evaluated in two small clinical studies. Littlewood et al, in an open-label case series of young CF patients treated with 500,000 U of colistin bid, suggested that the frequency of isolation of P aeruginosadecreased. Jensen et al randomized 40 patients to receive either colistin, 1 million units bid, or saline solution control for 90 days and found a slower rate of decline in FVC in treated patients. No adverse reactions to colistin were noted.