Colistimethate sodium is a cyclic polypeptide antibiotic of the polymyxin class. It binds to and damages the hydrophobic cell membrane of certain Gram negative bacteria.1
Colistimethate sodium dry powder for inhalation was evaluated in an open-label phase III clinical study involving 380 patients aged six years and above with cystic fibrosis and chronic P. aeruginosa lung infection. Patients were randomised to receive either one capsule containing 1.6625 million units of colistimethate sodium twice daily, or 300mg nebulised tobramycin twice daily for 24 weeks.1,2
Results showed that colistimethate sodium was non-inferior to tobramycin with respect to the primary efficacy endpoint of change in per cent predicted forced expiratory volume in one second (FEV1).1,2
Improvements in lung function
The mean change in per cent predicted FEV1 from baseline to week 24 was 0.964 in the colistimethate sodium group and 0.986 in the tobramycin group, representing a mean treatment difference of -0.98% (95% CI -2.74% to 0.86%).2
The most commonly reported adverse effects of colistimethate sodium were unpleasant taste, cough, throat irritation, dyspnoea and dysphonia.1,2
- Colobreathe Summary of Product Characteristics, February 2013.
- Schuster A et al. Thorax 2012; 0: 1–7.
Further information: Forest