[Reduction of urinary oxalate excretion by administration of calcium and citrate]

Oxalic acid seems to be more important for the formation of calcium oxalate stone than calcium. Three grams of calcium lactate and 3 g of uraly U were administered to 35 urolithiasis patients, whose stones were mainly composed of calcium oxalate. Urinary oxalate level was reduced significantly without raising urinary calcium level by the administration of the two drugs for two weeks. The reduction of oxalic acid was particularly remarkable in patients without hypercalciuria. The mechanism of action of these drugs and the relation to dietary management were discussed.