title: Sodium channel blockers for cystic fibrosis.
abstract: BACKGROUND
  People with cystic fibrosis (CF) have increased transport of the salt, sodium across their airway lining. Over-absorption of sodium results in the dehydration of the liquid that lines the airway surface and is a primary defect in people with CF.
  
  
  OBJECTIVE
  To determine whether the topical administration of drugs that block sodium transport improves the respiratory condition of people with CF.
  
  
  METHODS
  We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register comprising references identified from comprehensive electronic database searches, handsearching relevant journals and abstract books of conference proceedings. We contacted principal investigators known to work in the field, previous authors and pharmaceutical companies who manufacture ion transport agents for unpublished or follow-up data.Most recent search of the Group's register: 22nd August 2011.
  
  
  METHODS
  Published or unpublished randomised controlled trials (RCTs) or quasi-randomised controlled trials of sodium channel blockers compared to placebo or another sodium channel blocker or the same sodium channel blocker at a different dosing regimen.
  
  
  METHODS
  Two authors independently extracted data. Meta-analysis was limited due to differing study designs.
  
  
  RESULTS
  Five RCTs, with a total of 226 participants, examining the topical administration of the short-acting sodium channel blocker, amiloride, compared to placebo were identified as eligible for inclusion in the review. In three studies over six months, there was a significant difference found in the difference in relative change in FVC in favour of placebo (weighted mean difference 1.51% (95% confidence interval -2.77 to -0.25), although heterogeneity was evident. A two-week study demonstrated that hypertonic saline with amiloride pre-treatment did not result in a significant improvement in respiratory function or mucus clearance, in contrast to pre-treatment with placebo. There were no significant differences identified in other clinically relevant outcomes.
  
  
  CONCLUSIONS
  We found no evidence that the topical administration of a short-acting sodium channel blocker improves respiratory condition in people with cystic fibrosis and some limited evidence of deterioration in lung function.
authors.affiliation: Respiratory Department, Alder Hey Children’s NHS Foundation Trust, Liverpool, UK. elinor.burrows@alderhey.nhs.uk
authors.forename: Elinor F
authors.initials: EF
authors.lastname: Burrows
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Southern
authors.forename: Peadar G
authors.initials: PG
authors.lastname: Noone
mesh_terms: D000584:Amiloride / Q000008:administration & dosage / Q000627:therapeutic use*; D003550:Cystic Fibrosis / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D009093:Mucus / Q000378:metabolism; D016032:Randomized Controlled Trials as Topic; D012119:Respiration / Q000187:drug effects*; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage; D026941:Sodium Channel Blockers / Q000008:administration & dosage / Q000627:therapeutic use*; D014797:Vital Capacity / Q000187:drug effects / Q000502:physiology
chemical_list: D012462:Saline Solution, Hypertonic; D026941:Sodium Channel Blockers; D000584:Amiloride