By stimulating an enzyme, the sialyltransferase, Carbocisteine has a privileged place in mucomodifying therapeutics. It allows the substitution of pathologic secretions, congesting and aggressive, by physiologic restructured mucus. Tested with success in the E.N.T. catarrhal diseases, Rhinathiol interest is passed in review in each concerned pathologies. About interest of repairing mucociliary transport on the clinical symptomatology improvement.