Study design (if review, criteria of inclusion for studies)
Randomized, double-blind, placebo-controlled, cross-over design. 6 months on each intervention, followed by 3 months follow-up. Not ITT as 3 participants were excluded from the final analysis. Single centre in Denmark.
Participants
41 participants with CF (23 males). None were infected by Pseudomonas aeruginosa. Stable disease, but disease severity not stated. Exclusions: past history of peptic ulcer disease, liver or kidney disease and pregnancy. Age 2 - 31 years (mean 9.5).
Interventions
3 periods, each 3 months duration. First period oral NAC (200mg tid if <30kg, 400mg bid if >30kg) or placebo, then cross over to the other intervention, then 3 months follow up.
Outcome measures
Subjective scores of symptoms, body weight, sputum bacteriology and PFTs (FEV1, FVC, PEF) recorded every month. 3-monthly serum WBC, ESR and Staphylococcal aureus, Haemophilus influenzae and Pseudomonas aeruginosa antibody titres. Time on antibiotics also
Main results
No effect was seen in PCD patients, but in CF patients an improved lung function was seen in the period when the patients suffer most from lower airway infections.