Follow-up of drug therapy efficacy to prevent recurrence of calcium oxalate kidney stone formation.

Results of a prospective study of response to phosphate treatment after surgery in a group of kidney stone formers, some of them recurrent are presented. The follow-up, of 1 year duration, was carried out by periodic tests of the stone formers' urine using the Discriminating Index (DI) procedure. In a group of 32 stone formers, 30 individuals showed a remarkable change in the DI value; i.e., the inhibiting potential of their urine was similar to that of normals. Two of the patients did not respond well, and their drug treatment was adjusted accordingly. During this year no recurrency was reported.