Synonyms: 2(1H)-Quinolinone,8-hydroxy-5-[(1R,2S)-1-hydroxy-2-[(1-methylethyl)amino]butyl]-,monohydrochloride, rel- (9CI); 2(1H)-Quinolinone,8-hydroxy-5-[1-hydroxy-2-[(1-methylethyl)amino]butyl]-, monohydrochloride,(R*,S*)-(?à)-; 2(1H)-Quinolinone,8-hydroxy-5-[1-hydroxy-2-[(1-methylethyl)amino]butyl]-, monohydrochloride,(R*,S*)-; Meptin; OPC 2009; Procaterol hydrochloride