The Effect of Cellulose Phosphate on Intestinal Absorption and Urinary Excretion of Calcium: Some Experience in its use in the Treatment of Calcium Stone Formation

Abstract

The findings in a previous paper have provided further support for regimes of treatment which reduce the intestinal uptake of calcium and therefore its urinary excretion in the management of recurrent calcium urolithiasis (Blacklock and Macleod, 1974).Dietary measures have already been used towards this end and Nordin (1972) considers that a diet low in calcium and low in oxalates is the simplest and most effective approach in the treatment of this condition. Sodium phytate has been shown to form a relatively insoluble complex with calcium in the gut and the effect of this has been to lower urinary calcium in patients with idiopathic hypercalciuria (Henneman et al., 1958); there is however an increase in urinary phosphate excretion at the same time . Oral administration of sodium phosphate similarly has the effect of reducing intestinal calcium absorption and urinary calcium excretion but the urinary phosphorus excretion in the form of orthophosphate increases at the same time. Therapeutic use of both sodium phytate and sodium phosphate is therefore accompanied by a possibility of increased tendency to calcium phosphate precipitation on account of the increase in its activity product ratio. (Pak et al., 1971). The thiazides as a group reduce urinary calcium excretion and increase renal excretion of phosphate as pyrophosphate with a concomitant increase in the urinary sodium and potassium. Calcium balance studies carried out at the time of thiazide treatment suggest that calcium is retained during such treatment (Lamberg and Kuhlback, 1959; Lichwitz et al., 1961;Higgins et al., 1964; Yendt, Gagne and Cohamin, 1966;Harrison and Rose, 1968).Sodium cellulose phosphate, the sodium salt of the phosphoric ester of cellulose (Whatman Biochemicals Ltd) is an ion exchange cellulose with special affinity for divalent cations because of the steric configuration of the phosphate radicals attached to the cellulose molecule. In the stomach it exchanges sodium for calcium which is eliminated in the faeces so preventing the absorption of dietary calcium; it similarly binds with secreted calcium preventing its reabsorption. The diminution in calcium absorption is accompanied by a reduction in the renal excretion of calcium and a slight increase in urinary phosphorus but the urine saturation with brushite (CaHP04*2H20), a probable nidus for calcium stones, is reduced (Pak, 1973).This paper describes some observations on the effect of sodium cellulose phosphate on intestinal calcium uptake and urinary calcium excretion in patients with urolithiasis. Further observations are made on the results of a limited clinical application of the substance. Materials and Methods Clinical DataThe effect of cellulose phosphate was evaluated in a series of patients who exhibited intestinal hyperabsorption of calcium and hypercalciuria. All had full general and metabolic investigation including excretion urography. Cases of overt hyperparathyroidism were excluded.

The Cause of Idiopathic Calcium Stone Disease: Hypercalciuria or Hyperoxaluria?

“…Reduction of the calcium/oxalate ratio in the diet [18] or binding of calcium in the intestine by administration of ionexchangers such as cellulose phosphate [10,19] have a simi lar effect on oxalate absorption and excretion in the urine. In the light of the observations in this paper it is difficult to understand how treatment with cellulose phosphate will benefit the calcium oxalate stone-former, as suggested by some workers [5,23,24,31]. Indeed, a recent clinical study suggests that this form of therapy does not reduce the rate of calcium stone-formation over a period of 5 years [3].…”

Tumoral calcinosis: Evidence for concurrent defects in renal tubular phosphorus transport and in 1α,25-dihydroxycholecalciferol synthesis

“…After the control study, the patient was begun on sodium cellulose phosphate (SCP, 20 g/day in four divided doses orally with meals) for 12 days, while he was maintained on the same dietary regimen. This procedure was undertaken to determine whether the inhibition of intestinal Ca absorption produced by SCP treatment would stimulate endogenous parathyroid function and modify the renal handling of P [16]. Tests performed during this period included: fasting serum for Ca, P, and Cr every 2 days; daily urinary Ca and P; and serum for iPTH, 1,25-(OH).,D, 25-OHD, and 24,25-(OH).,D, TraP, and urinary cyclic AMP, on day 12 of SCP treatment.…”

Calculus disease of the urinary tract at a district hospital

“…It is suggested that the reason that the post-treatment mean is still in the hypercalciuric range is because the timing of drug therapy in relation to meals may not have been as exact as had been hoped. Blacklock and Macleod (1974) have emphasized how important this may be. While taking sodium cellulose phosphate, two patients reported minor gastrointestinal disturbances, one was nausea which ceased on stopping the drug and the other slight frequency of bowel action which settled when the drug was discontinued.…”