Treatment of recurrent calcium stone formation with cellulose phosphate.

Sodium cellulose phosphate was given to 35 patients for recurrent formation of calcium-containing stones. During therapy urinary calcium decreased by 40% in the first month and remained at this lower level. In addition, urinary magnesium excretion was reduced and the urinary magnesium/calcium ratio remained unaffected. In these patients, who mostly had had calcium oxalate stones, the prophylactic effects of sodium cellulose phosphate was poor, with a 47% recurrence rate after 2 years. This lack of prevention, despite the significant reduction of the urinary calcium, is assumed to be owing to the effects of treatment on magnesium and oxalate metabolism. Side effects were common, mainly consisting of moderate gastrointestinal discomfort, and caused withdrawal of treatment in 8 patients. This fact contributes further to our opinion that sodium cellulose phosphate is not the drug of choice in cases of calcium oxalate stone formation.