Antimicrobials in cystic fibrosis: emergence of resistance and implications for treatment.

We reviewed the current literature on the role of antibiotic therapy in cystic fibrosis, concentrating on studies directing therapy at Pseudomonas aeruginosa. To highlight controversial areas, we examined studies comparing monotherapy with combination therapy, home intravenous treatment versus hospital treatment, intravenous versus oral therapy, and the role of aerosolized antibiotics. We found that all systemic therapies with antipseudomonal activity were of comparable efficacy. Data on the efficacy of aerosolized treatment were equivocal. There is a substantial body of anecdotal literature addressing the issue of antibiotic resistance complicating treatment of cystic fibrosis. This will be briefly reviewed and the responsible mechanisms will be outlined. There is a secular trend for selection of more resistant pathogens in the lungs of CF patients. In the individual patient, however, emergence of antibiotic resistance may occur without deleterious clinical effects.