Use of the (-) stereoisomer of a compound of Formula I, wherein: R is a member selected from the group consisting of a hydroxy, lower aralkoxy, di-lower alkylamino-lower alkoxy, lower alkanamido lower alkoxy, benzamido-lower alkoxy, ureido-lower alkoxy, N'-lower alkyl-ureido-lower alkoxy, carbamoyl-lower alkoxy, halophenoxy substituted lower alkoxy, carbamoyl substituted phenoxy, carbonyl-lower alkylamino, N,N-di-lower alkylamino-lower alkylamino, halo substituted lower alkylamino, hydroxy substituted lower alkylamino, lower alkanolyloxy substituted lower alkylamino, ureido, and lower alkoxycarbonylamino； and each X is independently a halogen； or a pharmaceutically acceptable salt thereof, and €ƒ€ƒ€ƒwherein the (-) stereoisomer is substantially free of the (+) stereoisomer of the compound, in the preparation of a medicament for treating hyperuricemia in a mammal.
