VA Class:AD400
VA Class:GU900
Cellulose sodium phosphate is a phosphorylated cation-exchange resin used to prevent the intestinal absorption of calcium.1, 2, 3
Absorptive Hypercalciuria Type I
Cellulose sodium phosphate is used as an adjunct to dietary restriction in the management of absorptive hypercalciuria type I to reduce the frequency of new renal calculus (stone) formation.2, 5, 12, 18 Cellulose sodium phosphate is considered an orphan drug for the management of this condition;29, 30 absorptive hypercalciuria type I occurs rarely in the US, and safety and efficacy of the resin have only been determined in a limited number of patients.25, 26
In establishing the diagnosis of absorptive hypercalciuria type I, determinations of serum calcium and phosphorus concentrations, fasting (before breakfast) serum parathyroid hormone (PTH) concentration, 24-hour urinary calcium excretion when calcium and sodium intake are restricted, and fasting urinary excretion of calcium are the minimum diagnostic criteria.5 Absorptive hypercalciuria type I is characterized by recurrent passage or formation of renal calcium oxalate and/or calcium phosphate calculi;5, 16 no evidence of bone disease;5 normal serum calcium and phosphorus concentrations;5, 17 increased intestinal calcium absorption (e.g., urinary calcium/creatinine ratio of greater than 0.2 mg/mg after a 1-g oral load of calcium);5, 17 hypercalciuria (i.e., 24-hour urinary calcium excretion greater than 200 mg in patients receiving a restricted diet of 400 mg of calcium and 100 mEq of sodium daily);5 normal urinary calcium excretion under fasting conditions;5, 17 normal parathyroid function as evidenced by normal serum PTH concentration;5, 17 and lack of renal hypercalciuria or excessive skeletal mobilization of calcium.5
Unlike absorptive hypercalciuria type II, type I hypercalciuria does not respond to dietary calcium restriction alone.5, 17 Cellulose sodium phosphate is not recommended as an adjunct to dietary restriction in the management of absorptive hypercalciuria type II or hypercalciuria not caused by hyperabsorption of calcium.5, 15 In patients without hyperabsorption of calcium, cellulose sodium phosphate may be expected to cause malabsorption of calcium and subsequently cause a compensatory increase in PTH secretion, possibly resulting in hyperparathyroid bone disease.2, 5, 15, 16 (See Cautions: Precautions and Contraindications.)
In several studies in patients with absorptive hypercalciuria type I, cellulose sodium phosphate has effectively reduced the formation and/or passage of calcium-containing renal calculi.2, 12, 18 In one uncontrolled study in patients with absorptive hypercalciuria type I and recurrent calcium nephrolithiasis, 10-15 g of the resin daily with dietary calcium restriction for 1.5-4.8 years reduced renal calculus formation and passage from approximately 8 calculi per patient-year for the 3 years before therapy with the resin to 0.27 calculi per patient-year during therapy;12 81% of patients receiving the resin did not form new calculi.12 Although cellulose sodium phosphate has prevented new renal calculus formation in most patients with absorptive hypercalciuria type I and calcium nephrolithiasis,2, 12, 18 the rate of recurrence of renal calculus formation in patients with a history of calcium oxalate nephrolithiasis who received the resin for up to 3 years in one study did not differ from that in patients receiving no specific therapy and was greater than that in patients receiving thiazide diuretics;11 however, diagnosis of absorptive hypercalciuria type I was not confirmed in patients in this study.26 In addition, the high calculus recurrence rate observed in these patients may have resulted from administration of the resin at higher than recommended dosages and/or without dietary oxalate restriction and oral magnesium supplements,15 or the resin may be more effective for the management of calcium phosphate than calcium oxalate renal stones;11 the resin may increase intestinal absorption of oxalate (see Pharmacology: Effects on Phosphorus and Oxalate).9
For optimum effectiveness, cellulose sodium phosphate should be administered concomitantly (but not simultaneously) with oral magnesium supplements;5, 19 for oral supplementation, magnesium gluconate is generally preferred.5, 26 Fluid intake should be maintained at a level adequate to produce a minimum urinary output of 2 L daily, and dietary intake of calcium, oxalate, and ascorbic acid should be restricted.5, 19 In vitro, magnesium is a weak inhibitor of calcium oxalate crystallization27 and there is limited clinical evidence to suggest that a high urinary output of magnesium or a high urinary magnesium/calcium ratio reduces the risk of calcium oxalate stone formation in vivo.11 Since cellulose sodium phosphate inhibits magnesium absorption and may cause hypomagnesiuria, the resin may be less effective when administered without magnesium supplementation.11 In addition, therapy with cellulose sodium phosphate has resulted in hyperoxaluria which may reduce the effectiveness of the resin for the prevention of calcium oxalate stone formation.2, 11 Dietary intake of oxalate-containing foods (e.g., spinach, rhubarb, chocolate) should be restricted in patients receiving the resin.5, 15 Supplemental therapy with ascorbic acid also is not recommended in patients receiving the drug since this vitamin is metabolized to oxalate.5
Cellulose sodium phosphate appears to be as effective as thiazide diuretics for the management of absorptive hypercalciuria type I,21 but thiazides do not decrease hyperabsorption of calcium and may produce adverse effects on bone in patients with this condition.21 In one study, recurrence rates for renal calculi were higher in patients receiving the resin than in those receiving thiazides;11 however, diagnosis of absorptive hypercalciuria type I was not confirmed in these patients26 and those receiving the resin did not receive concomitant magnesium supplementation nor did they restrict their dietary oxalate intake during therapy.15, 26 Although cellulose sodium phosphate appears to be safe and effective for the management of absorptive hypercalciuria type I, some clinicians suggest that initial therapy with thiazide diuretics is preferred to that with cellulose sodium phosphate in patients with this condition.11, 19 Further comparative study is needed to determine the optimum therapy for the management of absorptive hypercalciuria type I.19
Cellulose sodium phosphate has been used as an adjunct in the management of hypercalcemia† (e.g., in patients with parathyroid carcinoma or sarcoidosis).3 In one study, moderate reductions in serum calcium concentrations were observed in hypercalcemic patients receiving 10 or 20 g of the resin daily.3
Cellulose sodium phosphate has also been used as an adjunct in the management of calcinosis cutis†.20 In one study in patients with this condition, plasma calcium concentrations decreased following therapy with 15 g of cellulose sodium phosphate daily.20 Although decreased stiffness and increased functional ability were reported in one patient with this condition receiving prolonged therapy with the resin, radiographic evidence of extensive calcification remained.20
Cellulose sodium phosphate is administered orally.5 Since the amount of calcium bound by cellulose sodium phosphate depends on the interaction of the resin with food in the GI tract, cellulose sodium phosphate should be given with meals.5 The amount of dietary calcium bound by cellulose sodium phosphate is substantially reduced when the resin is administered more than 1 hour after meals.1, 5 Commercially available cellulose sodium phosphate powder should be mixed with about 100-300 mL of water, soft drink, or fruit juice and ingested within 30 minutes of a meal.5, 26 The resin should not be mixed with milk or other beverages containing substantial amounts of cations.26
Although concomitant administration of cellulose sodium phosphate and oral magnesium supplements is recommended, these drugs should not be given simultaneously.5 Oral magnesium supplements should be administered at least 1 hour before or after a dose of cellulose sodium phosphate.5 Dietary intake of calcium, oxalate, and sodium should be restricted during therapy with the resin.5 (See Cautions: Precautions and Contraindications.) Fluid intake should be maintained at a level adequate to produce a minimum urinary output of 2 L daily during therapy with the resin.5
Dosage of cellulose sodium phosphate should be individualized according to determination of 24-hour urinary calcium excretion.5 Dosage of the resin that decreases calcium absorption to less than normal should be avoided.5 Each level scoop of the resin, using the calibrated scoop provided by the manufacturer, provides approximately 2.5 g of cellulose sodium phosphate.32
For the management of absorptive hypercalciuria type I with recurrent calcium nephrolithiasis in adults whose dietary calcium intake is restricted (i.e., avoidance of dairy products) and who have a urinary calcium excretion greater than or equal to 300 mg daily, the usual initial oral dosage of cellulose sodium phosphate is 15 g daily given in 3 equally divided doses with meals.5 When urinary calcium excretion decreases to less than 150 mg daily, dosage of the resin may be reduced to 10 g daily given in 3 divided doses (i.e., 5 g with the patient's largest meal and 2.5 g with each remaining meal).5, 26 In adults whose dietary calcium intake is moderately restricted and who have urinary calcium excretion less than 300 mg but greater than 200 mg daily, the usual initial dosage of cellulose sodium phosphate is 10 g daily given in 3 divided doses.5 It has been recommended that maximum dosage of the resin not exceed 20 g daily.26
For the prevention of hypomagnesiuria and/or hypomagnesemia, concomitant (but not simultaneous) administration of cellulose sodium phosphate and oral magnesium gluconate is recommended.5, 26 Dosage of magnesium gluconate should be adjusted individually according to dosage of cellulose sodium phosphate.5 The manufacturer recommends that patients receiving 15 g of cellulose sodium phosphate daily receive 1.5 g of magnesium gluconate twice daily.5 Patients receiving 10 g of cellulose sodium phosphate daily should receive 1 g of magnesium gluconate twice daily.5 Although it is suggested that magnesium gluconate be administered before breakfast and at bedtime,5the drug may be administered at any time that is convenient26 but at least 1 hour before or after the resin.5
Adverse GI effects occurring occasionally during therapy with cellulose sodium phosphate include loose bowel movements,5 diarrhea,5, 11, 13 dyspepsia,5 GI discomfort,11, 19 and intolerance to the commercially available preparation.5, 11 The resin has been discontinued in some patients because of the preparation's unpalatability.5
Hyperoxaluria has occurred in patients receiving cellulose sodium phosphate without dietary oxalate restriction.2, 9 Hypomagnesiuria has also been reported when the resin was administered without oral magnesium supplements.2, 11 The therapeutic effect of cellulose sodium phosphate may be decreased when hyperoxaluria and/or hypomagnesiuria occur in patients receiving the resin.5
Although not reported in clinical studies to date in patients receiving cellulose sodium phosphate, the potential exists for the resin to produce adverse effects on serum calcium and PTH concentrations.5
Hypomagnesemia has been reported rarely in patients receiving cellulose sodium phosphate.3, 13, 14, 28 Oral magnesium supplementation3 and/or reduction in resin dosage have been used for the prevention and management of this adverse effect.14
Acute arthritis has been reported in a few patients receiving cellulose sodium phosphate.11 Arthralgia resolved within a few weeks following discontinuance of the resin.11 Although a causal relationship to the resin has not been established, it has been suggested that symptoms of acute arthritis in patients receiving the resin may result from the development of pyrophosphate synovitis (pseudogout) that has been associated with calcium metabolic disease.11
Precautions and Contraindications
Cellulose sodium phosphate should only be used in carefully selected patients.5 Use of cellulose sodium phosphate should be limited to treatment of absorptive hypercalciuria type I to minimize the development of adverse effects.5 (See Uses.) Since cellulose sodium phosphate inhibits intestinal absorption of calcium, the resin may stimulate parathyroid function resulting in hyperparathyroid bone disease.5 Careful monitoring of parathyroid hormone (PTH) concentrations is essential during therapy with the resin.5 Serum PTH concentration should be determined before, at least once between the first 2 weeks to 3 months of therapy, and at 3- to 6-month intervals during therapy with the resin.5 Serum calcium concentration should also be determined before and at 3- to 6-month intervals during therapy with the resin.5 If borderline values for serum PTH and calcium concentrations are obtained during therapy with the resin, these determinations should be repeated promptly.5 Dosage of the resin should be adjusted or therapy discontinued if an increased serum PTH concentration occurs during therapy.5 Cellulose sodium phosphate reportedly does not adversely affect parathyroid function when a dosage minimally sufficient to restore normal calcium absorption is used in patients with absorptive hypercalciuria type I.5
Since hyperoxaluria, hypomagnesiuria, and depletion of magnesium or trace metals (e.g., copper, zinc, iron) are potential complications of long-term therapy with cellulose sodium phosphate, serum calcium, magnesium, copper, zinc, and iron concentrations and complete blood counts should be performed every 3-6 months during therapy with the resin.5 When cellulose sodium phosphate produces an inadequate hypocalciuric response after 1 week of therapy (a reduction in urinary calcium excretion of less than 30 mg per 5 g of the resin) in patients maintained on moderate calcium and sodium restriction, therapy with the resin should be considered ineffective and should be discontinued.5, 26 In addition, discontinuance of the resin should be considered if urinary oxalate excretion exceeds 55 mg daily in patients maintained on moderate dietary oxalate restriction.5
Patients receiving cellulose sodium phosphate should be advised to restrict their dietary intake of calcium by avoiding dairy products, and that of oxalate by avoiding spinach and similar dark greens, rhubarb, chocolate, and brewed tea.5 Because of its potential metabolism to oxalate, supplemental therapy with ascorbic acid is not recommended in patients receiving cellulose sodium phosphate.5 Patients should also be advised to restrict their dietary intake of sodium to less than 150 mEq daily by avoiding foods high in sodium and the use of added salt.5 Patients should be encouraged to increase their fluid intake to a level sufficient to maintain a minimum urinary output of 2 L daily.5
Cellulose sodium phosphate should be used with extreme caution, if at all, in patients with congestive heart failure or ascites since administration of the resin in these patients may represent a clinically important sodium load.5 (See Chemistry and Stability: Chemistry.)
Cellulose sodium phosphate is contraindicated in patients with primary or secondary hyperparathyroidism, including renal hypercalciuria (renal calcium leak).5 The resin is also contraindicated in patients with hypomagnesemia (serum magnesium concentration less than 1.5 mg/dL), bone disease (e.g., osteoporosis, osteomalacia, osteitis), hypocalcemia (e.g., hypoparathyroidism, intestinal malabsorption), enteric hyperoxaluria, or normal or decreased intestinal absorption and renal excretion of calcium.5 In addition, cellulose sodium phosphate is contraindicated in patients with increased urinary calcium concentration under fasting conditions or with hypophosphatemia, unless increased skeletal mobilization of calcium can be excluded.5
Because of increased requirements for dietary calcium in children, use of cellulose sodium phosphate in children younger than 16 years of age is not recommended.5 Cellulose sodium phosphate has been used as adjunctive therapy for osteopetrosis† in one child from age 3.5-5 years.24 When cellulose sodium phosphate was added to therapy that included prednisolone and a restricted calcium diet in this child, normal calcium balance was achieved initially; however, continued therapy with the resin was associated with the development of severe hypocalcemic tetany.24 To restore normal calcium balance in this child, short-term adjunctive therapy with parathyroid hormone was necessary.24
Mutagenicity and Carcinogenicity
In vitro studies to determine the mutagenic potential and long-term animal studies to determine the carcinogenic potential of cellulose sodium phosphate have not been performed to date.5, 26
Animal reproduction studies have not been performed with cellulose sodium phosphate.5 It is also not known whether the resin can cause fetal harm when administered to pregnant women.5 Because of increased requirements for dietary calcium in pregnant women, cellulose sodium phosphate should be used during pregnancy only when clearly needed.5
Although magnesium supplementation is recommended during cellulose sodium phosphate therapy, simultaneous oral administration of magnesium supplements and the resin should be avoided, since the resin may bind magnesium in the GI tract.5 To avoid binding of magnesium with cellulose sodium phosphate, magnesium supplements should be administered at least 1 hour before or after the resin.5 Cation-donating antacids or laxatives administered simultaneously with cellulose sodium phosphate may reduce the resin's calcium exchange capability.26
Because ascorbic acid may be metabolized to oxalate and excreted in urine, increased urinary excretion of oxalate may occur when cellulose sodium phosphate and ascorbic acid are administered concomitantly.5 Decreased effectiveness of cellulose sodium phosphate for the prevention of calcium oxalate stone formation may result when the resin is used concomitantly with ascorbic acid;5 therefore, supplemental ascorbic acid is not recommended in patients receiving the resin.5
Cellulose sodium phosphate is a cation-exchange resin that releases sodium in exchange for divalent cations in the intestine to form a nonabsorbable complex.2, 5, 7
Cellulose sodium phosphate inhibits intestinal absorption of calcium, resulting in decreased urinary calcium excretion.2, 5, 8 Following oral administration with meals, cellulose sodium phosphate binds dietary and secreted calcium in the intestine.5, 8 The resin substantially reduces the amount of calcium filtered by the kidneys.8 Since GFR does not change substantially during therapy with the resin, the reduction in the amount of calcium filtered probably results from decreased intestinal absorption of calcium and the resultant decrease in serum calcium concentration.8 Although slight decreases or no change in serum calcium concentration generally has been observed during therapy with cellulose sodium phosphate,1, 9, 10, 11, 12 substantial decreases in serum calcium concentration have been reported in some patients receiving the resin.3, 7 Each gram of cellulose sodium phosphate reduces urinary calcium excretion by approximately 10 mg.5 In vivo, the exchange capacity of cellulose sodium phosphate is also utilized for divalent cations other than calcium such as magnesium.5, 7 Thus, although 1 g of the resin has an in vitro exchange capacity of not less than 3.6 mEq of calcium,4 the in vivo exchange capacity is only about 0.7 mEq (13.3 mg) of calcium per g of resin.26
Cellulose sodium phosphate also binds dietary magnesium, resulting in decreased intestinal absorption5, 7 and urinary excretion of magnesium.2, 5, 7 Serum magnesium concentrations may decrease during therapy with cellulose sodium phosphate and hypomagnesemia has occurred in several patients receiving the resin without magnesium supplementation.3, 13, 14 (See Cautions: Other Adverse Effects.)
Although the effect of the resin on GI absorption has not been directly determined, cellulose sodium phosphate does not appear to inhibit the absorption of copper, zinc, or iron, since substantial changes in serum concentrations of these cations have not been observed following oral administration of the resin.5, 8, 9, 12, 26
Effects on Phosphorus and Oxalate
Following oral administration of cellulose sodium phosphate, urinary concentrations of phosphorus increase.7, 8 Intestinal absorption of phosphorus increases as phosphate is released during partial hydrolysis of cellulose sodium phosphate in the GI tract, resulting in increased urinary phosphate excretion.7, 8 (See Pharmacokinetics: Elimination.) Each gram of the resin increases urinary phosphorus excretion by about 10-16.6 mg.5
Increased urinary excretion of oxalate may occur during therapy with cellulose sodium phosphate.2, 9, 23 Since the resin binds divalent cations in the intestine, the intraluminal availability of these cations to complex with oxalate (e.g., calcium-oxalate complex)2, 5, 9 and thereby prevent oxalate's intestinal absorption is decreased, resulting in increased absorption of free oxalate.2, 9
Cellulose sodium phosphate inhibits renal calculus (stone) formation by decreasing the saturation of urine with calcium phosphate and calcium oxalate.8, 10, 23 The degree of saturation is estimated from the urinary activity products of calcium and phosphate8 and calcium and oxalate ions.23 The resin generally reduces the urinary activity product ratio of calcium phosphate, thereby decreasing the saturation of urine.8, 10 The urinary activity product ratio of calcium oxalate may decrease or not change substantially, since therapy with the resin increases urinary oxalate excretion.23 However, the effect of decreased urinary calcium excretion induced by cellulose sodium phosphate on the activity product is usually greater than that of increased GI absorption and subsequent excretion of oxalate induced by the resin.23 Although urine reportedly has remained supersaturated with calcium oxalate in some patients during therapy with the resin, the incidence of calcium oxalate renal calculi has been reduced in these patients.23 Reduction in urinary calcium concentration with only slight increases in urinary phosphate and oxalate concentrations decreases the propensity for spontaneous nucleation of calcium oxalate and calcium phosphate (brushite).5, 8, 10 It has been suggested that prevention of the formation of brushite (the initial nidus of calcium phosphate) may also inhibit development of calcium oxalate stones produced by heterogeneous nucleation.23
Serum alkaline phosphatase (bone origin) concentration may increase slightly during therapy with the resin; however, these values usually remain within normal limits.9, 11
Therapy with cellulose sodium phosphate at dosages just sufficient to restore normal calcium absorption generally does not affect parathyroid hormone (PTH) concentration in patients with hyperabsorption of calcium,9, 12, 15 but the potential exists for the resin to cause excessive PTH secretion and hyperparathyroidism in patients without hyperabsorption of calcium.5
Slight increases in renal cyclic 3',5'-adenosine monophosphate (cAMP) have occurred in some patients receiving cellulose sodium phosphate;9, 11, 22 however, these values usually remain within normal limits.9, 11
Cellulose sodium phosphate is not absorbed from the GI tract.5 Phosphorus that has been hydrolyzed from the resin may be absorbed.5 (See Pharmacokinetics: Elimination.)
Cellulose sodium phosphate undergoes partial hydrolysis (7-30%) in the intestine which causes release of phosphorus ions.3, 5, 7, 8 Following oral administration of 15 g of cellulose sodium phosphate, urinary phosphorus excretion usually increases by about 150-250 mg.5 The resin also undergoes cationic modification in the intestine, exchanging calcium and magnesium for sodium.1, 2, 5 The nonabsorbable cationically modified resin and unchanged resin are excreted in feces.5, 10
Cellulose sodium phosphate is a phosphorylated cation-exchange resin used to prevent the intestinal absorption of calcium.1, 2, 3 Cellulose sodium phosphate is a synthetic sodium salt of the phosphate ester of cellulose1, 2, 3 that is prepared by phosphorylation of alpha cellulose.31 Each gram of the resin has an in vitro exchange capacity of not less than 3.6 mEq (1.8 mmol) of calcium calculated on the dried basis.31
Cellulose sodium phosphate occurs as a free-flowing, cream-colored, odorless, tasteless powder4 and is insoluble in water4, 5 and in dilute acids.4 The resin has an inorganic bound phosphate content of about 33.5% (31-36%), a free phosphate content of not more than 3.5%, and a sodium content of about 11.3% (9.5-13%), calculated on the dried basis.5, 31 Each gram of the powdered resin contains approximately 2.3-3.2 mEq of exchangeable sodium.5 When the resin is mixed with water and then filtered through a sintered-glass filter, the filtrate has a pH of 6-9.31
Cellulose sodium phosphate powder hydrolyzes slowly upon standing.6 Cellulose sodium phosphate powder should be protected from moisture and stored in well-closed containers31 at 15-30°C.5, 25
Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.
Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations.
1. Blacklock NJ, Macleod MA. The effect of cellulose phosphate on intestinal absorption and urinary excretion of calcium. Br J Urol . 1974; 46:385-92. [PubMed 4416182]
2. Hautmann R, Hering FJ, Lutzeyer W. Calcium oxalate stone disease: effects and side effects of cellulose phosphate and succinate in long-term treatment of absorptive hypercalciuria or hyperoxaluria. J Urol . 1978; 120:712-5. [PubMed 731812]
3. Pak CY, Wortsman J, Bennett JE et al. Control of hypercalcemia with cellulose phosphate. J Clin Endocrinol Metab . 1968; 28:1829-32.
4. The United States pharmacopeia, 21st rev, and The national formulary, 16th ed. Suppl 1. Rockville, MD: The United States Pharmacopeial Convention, Inc; 1985:1779.
5. Mission Pharmacal Company. Calcibind® prescribing information. San Antonio, TX; 1988 Jan.
6. Reynolds JEF, ed. Martindale: the extra pharmacopoeia. 28th ed. London: The Pharmaceutical Press; 1982:391.
7. Berstad A, Jorgensen H, Frey H et al. The acute effect of sodium cellulose phosphate on intestinal absorption and urinary excretion of calcium in man. Acta Med Scand . 1975; 197:361-5. [PubMed 1146614]
8. Pak CYC. Sodium cellulose phosphate: mechanism of action and effect on mineral metabolism. J Clin Pharmacol . 1973; 13:15-27.
9. Pak CYC. Clinical pharmacology of sodium cellulose phosphate. J Clin Pharmacol . 1979; 19:451-7. [PubMed 489764]
10. Pak CYC, Cox JW, Powell E et al. Effect of the oral administration of ammonium chloride, sodium phosphate, cellulose phosphate and parathyroid extract on the activity product of brushite in urine. Am J Med . 1971; 50:67-76. [PubMed 5539578]
11. Backman U, Danielson BG, Johansson G et al. Treatment of recurrent calcium stone formation with cellulose phosphate. J Urol . 1980; 123:9-13. [PubMed 7351731]
12. Pak CYC, Delea CS, Bartter FC. Successful treatment of recurrent nephrolithiasis (calcium stones) with cellulose phosphate. N Engl J Med . 1974; 290:175-80. [PubMed 4808916]
13. Dent CE, Harper CM, Parfitt AM. The effect of cellulose phosphate on calcium metabolism in patients with hypercalciuria. Clin Sci . 1964; 27:417-25. [PubMed 14236779]
14. Sutton RAL. Hypomagnesaemia and magnesium deficiency. J R Coll Physicians London . 1968; 2:358-70.
15. Pak CYC. A cautious use of sodium cellulose phosphate in the management of calcium nephrolithiasis. Invest Urol . 1981; 19:187-90. [PubMed 7298289]
16. Anon. Sodium cellulose phosphate approved for absorptive hypercalciuria. FDA Drug Bull . 1983; 13:1-2. [PubMed 6852405]
17. Pak CYC, Britton F, Peterson R et al. Ambulatory evaluation of nephrolithiasis: classification, clinical presentation and diagnostic criteria. Am J Med . 1980; 69:19-30. [PubMed 6247914]
18. Pak CYC, Peters P, Hurt G et al. Is selective therapy of recurrent nephrolithiasis possible? Am J Med . 1981; 71:615-22. (IDIS 142353)
19. Anon. Sodium cellulose phosphate (Calcibind). Med Lett Drugs Ther . 1983; 25:67-8. [PubMed 6865849]
20. Marks J. Studies with47Ca in patients with calcinosis cutis. Br J Dermatol . 1970; 82:1-9. [PubMed 5410989]
21. Pak CYC. Medical management of nephrolithiasis. J Urol . 1982; 128:1157-64. [PubMed 6759686]
22. Malluche HH, Tschoepe W, Ritz E et al. Abnormal bone histology in idiopathic hypercalciuria. J Clin Endocrinol Metab . 1980; 50:654-8. [PubMed 6245099]
23. Hayashi Y, Kaplan RA, Pak CYC. Effect of sodium cellulose phosphate therapy on crystallization of calcium oxalate in urine. Metabolism . 1975; 24:1273-8. [PubMed 241892]
24. Dent CE, Smellie JM, Watson L. Studies in osteopetrosis. Arch Dis Child . 1965; 40:7-15. [PubMed 14259278][PubMedCentral]
25. Alexandrides G (Mission Pharmacal Company, San Antonio, TX): Personal communication; 1984 Jun 18.
26. Pak CYC (Consultant to Mission Pharmacal Company, San Antonio, TX): Personal communication; 1984 Jun 11.
27. Meyer JL, Smith LH. Growth of calcium oxalate crystals—inhibition by natural urinary crystal growth inhibitors. Invest Urol . 1975; 15:36-9.
28. Pietrek J, Kokot F. Treatment of patients with calcium-containing renal stones with cellulose phosphate. Br J Urol . 1973; 45:136-43. [PubMed 4706494]
29. Marwick C. New drugs selectively inhibit kidney stone formation. JAMA . 1983; 250:321-2. [PubMed 6854890]
30. US Public Health Service. Annual report: activities of the orphan products board, March 1982-May 1983. 1983:[19]. Available from: Food and Drug Administration, Rockville, MD.
31. The United States pharmacopeia, 21st rev, and The national formulary, 16th ed. Suppl 2. Rockville, MD: The United States Pharmacopeial Convention, Inc; 1985:1825.
32. Cohen D (Mission Pharmacal Company, San Antonio, TX): Personal communication; 1989 Apr 6.