A double-blind placebo controlled trial with oral ambroxol and N-acetylcysteine for mucolytic treatment in cystic fibrosis.

The therapeutic efficacy of oral N-acetylcysteine (NAC) and ambroxol as compared with the effect of placebos was studied in 36 cystic fibrosis (CF) patients with mild to moderate pulmonary disease. The patients were randomly assigned to one of three regimens, matched on the basis of age and Chrispin-Norman scores. The trial was conducted over a period of 12 weeks. Patients were assessed clinically and by extensive pulmonary function techniques (body-plethysmography, maximal expiratory flow-volume curves, trapped air determination). Although no clinical differences could be observed between the three groups, significant impairment in the placebo group was found for trapped air and FEV1 when compared to the active groups, suggesting a therapeutic effect of ambroxol and NAC in CF.