Colistimethate Sodium Dry Powder for Inhalation: A Review of Its Use in the Treatment of Chronic Pseudomonas aeruginosa Infection in Patients with Cystic Fibrosis

Daniel Conole, Gillian M. Keating

Historically, the polymyxin antibacterial colistin has been administered as intravenous or nebulized colistimethate sodium in patients with cystic fibrosis (CF) and chronic Pseudomonas aeruginosa infection. More recently, colistimethate sodium has been formulated as a dry powder (Colobreathe(®)) to be administered via a hand-held Turbospin(®) inhaler. Compared with nebulized colistimethate sodium, the colistimethate sodium dry powder for inhalation (DPI) formulation reduces treatment time and improves patient convenience. Colistimethate sodium DPI is approved in the EU for the treatment of chronic P. aeruginosa infections in patients with CF aged ≥6 years. In a phase III clinical trial in this patient population, it was determined that the change in percent predicted forced expiratory volume in 1 s with colistimethate sodium DPI 1.6625 MIU (125 mg) twice daily was noninferior to that with nebulized tobramycin 300 mg/5 mL twice daily. Moreover, patients found colistimethate sodium DPI easier to use than nebulized tobramycin. Colistimethate sodium DPI was generally well tolerated, with a similar adverse event profile to that of nebulized tobramycin, except for a numerically higher incidence of cough and abnormal taste. Most adverse events diminished after 28 days in patients receiving colistimethate sodium DPI, with an occurrence similar to that in nebulized tobramycin recipients. In conclusion, colistimethate sodium DPI administered via the Turbospin® inhaler is a useful option for the treatment of chronic P. aeruginosa infection in patients with CF aged ≥6 years.