Chronic bacterial
respiratory-tract infections are a major driving force in the pathogenesis of
cystic fibrosis (CF)
lung disease and promote chronic lung-function decline, destruction, and progression to
respiratory failure at a premature age. Gram-negative bacteria colonizing the airways in CF are a major problem in CF
therapy due to their tendency to develop a high degree of resistance to
antibiotic agents over time. Pseudomonas aeruginosa is the dominating bacterial strain infecting the CF lung from early childhood on, and multiresistant strains frequently develop after years of
therapy.
Colistin has been used for treating pulmonary
bacterial infections in CF for decades due to its very good Gram-negative activity. However, drawbacks include concerns regarding toxicity when being applied systemically, and the lack of approval for application by inhalation in the USA for many years. Other
antibiotic substances for systemic use are available with good to excellent Gram-negative and anti-Pseudomonas activity, while there are only three substances approved for inhalation use in the treatment of chronic pulmonary
infection with proven benefit in CF. The emergence of multiresistant strains leaving nearly no
antibiotic substance as a treatment option, the limited number of
antibiotics with high activity against P. aeruginosa, the concerns about increasing the risk of antibiotic resistance by continuous
antibiotic therapy, the development of new
drug formulations and
drug-delivery devices, and, finally, the differing treatment strategies used in CF centers call for defining the place of this "old"
drug,
colistimethate, in today's CF
therapy. This article reviews the available evidence to reflect on the place of
colistimethate sodium in the
therapy of chronic pulmonary
infection in CF.