Disclosed is the use of 10-[3R)-1-azabicyclo[2.2.2]oct-3-ylmethyl]-10H-phenothiazine, 10-[(3S)-1-azabicyclo[2.2.2]oct-3-ylmethyl]-10H-phenothiazine or 10-[(3R, 3S)-1-azabicyclo[2.2.2]oct-3-ylmethyl]-10H-phenothiazine, or a pharmaceutically acceptable salt thereof, as sole active principal, to prepare a drug to prevent or treat obstructive bronchopneumopathy.