The use is claimed of substituted 3,5-diphenyl-1,2,4-triazole derivatives of formula (I), or their salts, for treating diseases which cause an excess of metal in the body, or are caused by it. R1, R5 = H, halo, OH, 1-7C alkyl, halo-(1-7C alkyl), 1-7C alkoxy, halo-(1-7C alkoxy), carboxyl, carbamoyl, N-(1-7C alkyl)carbamoyl, N,N-di(1-7C alkyl)carbamoyl or CN； R2, R4 = H, optionally substituted 1-7C alkanoyl or aroyl, or a radical which can be removed under physiological conditions； R3 = H, 1-7C alkyl, hydroxy-(1-7C alkyl), halo-(1-7C alkyl), carboxy-(1-7C alkyl), 1-7C alkoxycarbonyl-(1-7C alkyl), R6R7NC(O)(1-7C alkyl), optionally substituted aryl or aryl-(1-7C alkyl), or optionally substituted heteroaryl or hetero-aralkyl； R6, R7 = H, 1-7C alkyl, hydroxy-(1-7C alkyl), alkoxy-(1-7C alkyl), hydroxyalkoxy(1-7C alkyl), amino-(1-7C alkyl), N-(1-7C alkyl)amino-(1-7C alkyl), N,N-di(1-7C alkyl)amino-(1-7C alkyl), N(hydroxy-(1-7C alkyl))amino-(1-7C alkyl) or N,N-di(hydroxy-(1-7C alkyl))amino-(1-7C alkyl)； or NR6R7 = an aza-alicyclic ring. Also claimed are new compounds (IA), i.e. (I) where R3 = R6R7N-C(O)-(1-7C alkyl), optionally substituted aryl, aryl-(1-7C alkyl), substituted by N-(1-7C alkyl)amino, N,N-di(1-7C alkyl)amino or pyrrolidino, or optionally substituted heteroaryl or hetero-aralkyl； provided that R3 is not Ph or Ph substituted by halo, NO2, CN, OH, 1-7C alkyl, halo-(1-7C alkyl), 1-7C alkoxy or 1-7C alkoxycarbonyl if R2 and R4 are H, and R1 and R5 are H, halo, 1-7C alkyl, halo-(1-7C alkyl), 1-7C alkoxy or CN.
