OBJECTIVES: I. Evaluate the ability of a slow-releasing formulation of neutral potassium phosphate to correct hypercalciuria and prevent recurrent stone formation in patients with absorptive hypercalciuria. II. Evaluate the safety of this treatment. III. Compare the efficacy of potassium phosphate to that of potassium citrate.

Condition	Treatment or Intervention	Phase
Hypercalciuria Kidney Calculi	Drug: potassium citrate  Drug: potassium phosphate	Phase III

Further Study Details: 

Expected Total Enrollment:  300

PROTOCOL OUTLINE: This is a randomized, double-blind study. Patients are stratified by participating institution. Patients receive potassium phosphate or potassium citrate tablets twice a day for 3 years.

Ages Eligible for Study:  18 Years and above,  Genders Eligible for Study:  Both

Criteria

PROTOCOL ENTRY CRITERIA: --Disease Characteristics-- Absorptive hypercalciuria Intestinal hyperabsorption of calcium, i.e.: Exaggerated calciuric response to oral calcium load OR Fractional calcium-47 absorption greater than 0.61 Calciuria greater than 200 mg/day on random and calcium-restricted diet Normal or high fasting urinary calcium Normal serum calcium Normal serum parathyroid hormone No primary hyperparathyroidism At least 1 calcium oxalate stone within the past 3 years No struvite or carbonate apatite stones No noncalcareous stones No numerous stones making precise quantitation difficult No renal tubular acidosis --Prior/Concurrent Therapy-- No concurrent drug therapy for nephrolithiasis --Patient Characteristics-- Creatinine clearance at least 0.7 mL/min per kilogram No hyperkalemia No hyperphosphatemia No urinary tract infection Other: No predisposition to hyperkalemia, including concurrent use of the following drugs: Potassium-sparing diuretics Angiotensin-converting enzyme inhibitors Nonsteroidal anti-inflammatory drugs No active peptic ulcer disease No chronic diarrhea

Study chairs or principal investigators

Charles Y. C. Pak,  Study Chair,  University of Texas   

Study ID Numbers:  199/11703; UTSMC-039510400
Record last reviewed:  June 2000
Last Updated:  October 13, 2004
Record first received:  October 18, 1999
ClinicalTrials.gov Identifier:  NCT00004284
Health Authority: United States: Federal Government
ClinicalTrials.gov processed this record on 2005-04-08