The present invention relates to the use of a Compound of formula I, preferably 4-[3, 5-bis (2-hydroxyphenyl)-[1, 2, 4]triazol-1-yl] benzoic acid or a pharmaceutically acceptable salt thereof for the preparation of a medicament for use in the treatment of biofilm formation, e. g. of P. aeruginosa, e. g. in cystic fibrosis patients.本發明係關於一種以式I化合物較佳為4-[3,5-雙(2-羥苯基)-[1,2,4]三唑-1-基]苯甲酸或其醫藥學上可接受之鹽,於製備適用於治療例如囊腫性纖維化患者之(例如綠膿桿菌(P. aeruginosa))生物膜形成之藥物上的用途。