The present invention relates to the use of a histamine H4 agonist molecule, the enantiomers of the (AMINO-7 TRIETHOXY-4,5,6 OXO-1 DIHYDRO-1,3 ISOBENZOFURANNYL-3)-1METHOXY-8 METHYL-2 METHYLENEDIOXY-6,7 TETRAHYDRO-,2,3,4 ISOQUINOLINE or tritoqualine for the treatment of respiratory impairment caused by cystic fibrosis and the reduction and prevention of bronchial superinfections.