Study design (if review, criteria of inclusion for studies)
Randomized, single-blind, parallel-group design.
Participants
26 CF participants (12 males). Good clinical status (Schwachmann index 76.2 (2.8) in the SCMS-Lys group, 77.3 (3.5) in the ABX group) Age range 8 - 26 years (mean (SE) 15.9 (1.7) years in the SCMS-Lys group, 16.2 (1.5) years in the ABX group). "Concomitant administration of antitussives, muco-actives, sedatives, H1-receptor antagonists and systemic corticosteroids was not allowed during the study".
Interventions
One group received SCMS-Lys at a dose of 900mg tid in adults and 270mg tid in children under 14 years of age. The other group received oral ABX at dose of 33mg tid in adults and 10 mg qid in children under 14 years of age.
Outcome measures
At baseline, 20, 40, 60 and 80 days of the intervention period, participants had the following assessments performed: Viscosity and elasticity of expectorated sputum as assessed by an "oscillometric visco-elastometer". Cough frequency, "intensity of dyspnoea/tachypnoea" and chest sound abnormalities as assessed and rated on a 5-point digital scale (1 = greatest degree of abnormality, 5 = absence of symptom or sign). Estimated sputum volume over the preceding 24-hour period was also rated (1 = >50 mls/day, 2 = 25-50 mls/day, 3 = <25 mls/day, 4 = 'little or no expectorate'). Arterial blood gas analysis. Assessment of adverse effects. In addition, the Shwachmann score was assessed at baseline and at 80 days. Tidal volume, FEV1, PEF, MEF25, MEF50, MEF75 and 'Tiffeau index'.
Main results
at the end of this control period both groups showed significant improvement in chest sound score but improvement in cough score was observed only in those receiving SCMC-Lys. Expectorate viscosity and elasticity decreased significantly in both groups. In SCMC-Lys-treated patients paCO2 decreased and paO2 and Hb O2 saturation increased while only paO2 increased significantly in those treated with ABX. An increase in tidal volume, peak expiratory flow values and forced expiratory volume were evident in those receiving SCMC-Lys while significant increases in forced expiratory flow were recorded in those receiving ABX. SCMC-Lys patient's Shwachmann index improved significantly and conversely to the ABX patients. No adverse events were recorded in either treatment group.
Authors' conclusions
SCMC-Lys is at least as effective as ABX in improving respiratory function in patients with cystic fibrosis.