A cautious use of sodium cellulose phosphate in the management of calcium nephrolithiasis

Oral sodium cellulose phosphate, an inhibitor of intestinal calcium absorption, may reduce urinary magnesium, increase urinary oxalate, and have a limited hypocalciuric action or cause negative calcium balance in the absence of increased calcium absorption or in the presence of renal calcium "leak". To overcome these potential complications, we have taken the following precautions: oral magnesium supplements were given, a moderate oxalate restriction was imposed, a modest dose of sodium cellulose phosphate was used (usually 10 g per day), and only patients with documented absorptive hypercalciuria were treated. During a cumulative treatment period of 42.8 years, 18 patients with recurrent calcium nephrolithiasis showed a sustained reduction in urinary calcium, without developing consistent or substantial reduction in urinary magnesium, hyperoxaluria, hyperparathyroidism, or reduced bone density, Urinary saturation (relative saturation ratio) of calcium oxalate and brushite typically decreased. Remission of stone disease was found in 78 per cent of patients. We conclude that sodium cellulose phosphate is a useful drug for absorptive hypercalciuria when used appropriately.