Five years of experience with selective therapy in recurrent calcium nephrolithiasis

We evaluated the efficacy of selective treatment in 126 patients with recurrent calcium urolithiasis who were chosen on the basis of ability to correct underlying physiochemical disturbances. Patients with hyperparathyroidism underwent an operation. Patients with renal hypercalciuria were treated with thiazide and those with absorptive hypercalciuria were given a low calcium, low oxalate diet with or without thiazide. The only treatment for normocalciuric patients was high fluid intake, which was suggested also to the other groups. A significant individual mean reduction in stone formation was observed in all groups after 5 years of treatment. However, only 48 per cent of the normocalciuric patients were in remission after 5 years of high fluid intake therapy and 45 per cent of those with absorptive hypercalciuria were free of recurrence with diet only. Thiazide treatment seemed to be effective despite the type of hypercalciuria. The effect of the treatment on stone formation was mediated through reduction of risk factors in the urine. Conversely, a high level of risk factors commonly predicted stone recurrence.