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known to work in the field, previous authors and pharmaceutical companies who manufacture ion transport agents for unpublished or follow-up data.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: March 2006
  
  
  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  Published or unpublished randomised controlled trials (RCTs) or quasi-randomised controlled trials of sodium channel blockers compared to placebo or another sodium channel blocker or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
  Four RCTs, with a total of 205 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. For three studies, interventions for six months were completed and it was possible to calculate relative change in respiratory function (FVC). There was a significant difference found in relative change in FVC in favour of placebo (GIV analysis of weighted mean difference for FVC; 1.51% (95% confidence interval -2.77 to -0.25). 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: Alder Hey Children's Hospital, Respiratory Department, Eaton Road, Liverpool, Merseyside, UK L12 2AP. elinor.burrows@rlc.nhs.uk
authors.forename: E
authors.initials: E
authors.lastname: Burrows
authors.forename: K W
authors.initials: KW
authors.lastname: Southern
authors.forename: P
authors.initials: P
authors.lastname: Noone
mesh_terms: D003550:Cystic Fibrosis / Q000188:drug therapy*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D026941:Sodium Channel Blockers / Q000627:therapeutic use*
chemical_list: D026941:Sodium Channel Blockers